Computations of Derivatives
Computations of Derivatives 
The algebra for computing derivatives using the limit 
approach gets unmanageable fast.
Computations of Derivatives 
The algebra for computing derivatives using the limit 
approach gets unmanageable fast. 
Elementary functions are built in finitely many steps 
using a few basic formulas, the real numbers and 
the algebraic operations +,–, *, / and function 
composition
Computations of Derivatives 
The algebra for computing derivatives using the limit 
approach gets unmanageable fast. 
Elementary functions are built in finitely many steps 
using a few basic formulas, the real numbers and 
the algebraic operations +,–, *, / and function 
composition–plug in a formula into another formula.
Computations of Derivatives 
The algebra for computing derivatives using the limit 
approach gets unmanageable fast. 
Elementary functions are built in finitely many steps 
using a few basic formulas, the real numbers and 
the algebraic operations +,–, *, / and function 
composition–plug in a formula into another formula. 
It’s because of their structures that elementary 
functions are the ones we are able to find derivatives 
easily.
Computations of Derivatives 
The algebra for computing derivatives using the limit 
approach gets unmanageable fast. 
Elementary functions are built in finitely many steps 
using a few basic formulas, the real numbers and 
the algebraic operations +,–, *, / and function 
composition–plug in a formula into another formula. 
It’s because of their structures that elementary 
functions are the ones we are able to find derivatives 
easily. 
The operation of taking derivatives is called 
differentiation.
Computations of Derivatives 
The algebra for computing derivatives using the limit 
approach gets unmanageable fast. 
Elementary functions are built in finitely many steps 
using a few basic formulas, the real numbers and 
the algebraic operations +,–, *, / and function 
composition–plug in a formula into another formula. 
It’s because of their structures that elementary 
functions are the ones we are able to find derivatives 
easily. 
The operation of taking derivatives is called 
differentiation. We will examine how the operation of 
differentiation behaves under the above operations.
Computations of Derivatives 
The following properties of limits pass on directly to 
the differentiation operation.
Computations of Derivatives 
The following properties of limits pass on directly to 
the differentiation operation. These are the sum, 
difference, and constant multiplications rules of limits: 
lim (f ± g) = lim f ± lim g and that lim c(f) = c lim f
Computations of Derivatives 
The following properties of limits pass on directly to 
the differentiation operation. These are the sum, 
difference, and constant multiplications rules of limits: 
lim (f ± g) = lim f ± lim g and that lim c(f) = c lim f 
It’s important to point out here that the corresponding 
product and quotient properties of limits do not pass 
on to the differentiation operation.
Computations of Derivatives 
The following properties of limits pass on directly to 
the differentiation operation. These are the sum, 
difference, and constant multiplications rules of limits: 
lim (f ± g) = lim f ± lim g and that lim c(f) = c lim f 
It’s important to point out here that the corresponding 
product and quotient properties of limits do not pass 
on to the differentiation operation. The product and 
quotient rules of differentiation are more complicated.
Computations of Derivatives 
The following properties of limits pass on directly to 
the differentiation operation. These are the sum, 
difference, and constant multiplications rules of limits: 
lim (f ± g) = lim f ± lim g and that lim c(f) = c lim f 
It’s important to point out here that the corresponding 
product and quotient properties of limits do not pass 
on to the differentiation operation. The product and 
quotient rules of differentiation are more complicated. 
Unless stated otherwise, we assume that the 
derivatives at x exist in all the theorems below.
Computations of Derivatives 
The following properties of limits pass on directly to 
the differentiation operation. These are the sum, 
difference, and constant multiplications rules of limits: 
lim (f ± g) = lim f ± lim g and that lim c(f) = c lim f 
It’s important to point out here that the corresponding 
product and quotient properties of limits do not pass 
on to the differentiation operation. The product and 
quotient rules of differentiation are more complicated. 
Unless stated otherwise, we assume that the 
derivatives at x exist in all the theorems below. 
The ± and Constant–Multiple Derivative Rules
Computations of Derivatives 
The following properties of limits pass on directly to 
the differentiation operation. These are the sum, 
difference, and constant multiplications rules of limits: 
lim (f ± g) = lim f ± lim g and that lim c(f) = c lim f 
It’s important to point out here that the corresponding 
product and quotient properties of limits do not pass 
on to the differentiation operation. The product and 
quotient rules of differentiation are more complicated. 
Unless stated otherwise, we assume that the 
derivatives at x exist in all the theorems below. 
The ± and Constant–Multiple Derivative Rules 
Let f(x) and g(x) be two functions then
Computations of Derivatives 
The following properties of limits pass on directly to 
the differentiation operation. These are the sum, 
difference, and constant multiplications rules of limits: 
lim (f ± g) = lim f ± lim g and that lim c(f) = c lim f 
It’s important to point out here that the corresponding 
product and quotient properties of limits do not pass 
on to the differentiation operation. The product and 
quotient rules of differentiation are more complicated. 
Unless stated otherwise, we assume that the 
derivatives at x exist in all the theorems below. 
The ± and Constant–Multiple Derivative Rules 
Let f(x) and g(x) be two functions then 
i. (f(x)±g(x)) ' = f '(x)±g '(x) 
ii. (cf(x)) ' = c*f '(x) where c is a constant.
Computations of Derivatives 
To verify i, note that 
= 
(f(x) + g(x)) '
Computations of Derivatives 
To verify i, note that 
lim 
[f(x+h) + g(x+h)] – [f(x) + g(x)] 
h →0 h 
= 
(f(x) + g(x)) '
Computations of Derivatives 
To verify i, note that 
lim 
[f(x+h) + g(x+h)] – [f(x) + g(x)] 
h →0 h 
= 
(f(x) + g(x)) ' 
lim [f(x+h) – f(x)] + [g(x+h) – g(x)] 
h h →0 
=
Computations of Derivatives 
To verify i, note that 
lim 
[f(x+h) + g(x+h)] – [f(x) + g(x)] 
h →0 h 
= 
(f(x) + g(x)) ' 
lim [f(x+h) – f(x)] + [g(x+h) – g(x)] 
h h →0 
= 
lim [f(x+h) – f(x)] [g(x+h) – g(x)] 
= + 
h 
h →0 
h
Computations of Derivatives 
To verify i, note that 
lim 
[f(x+h) + g(x+h)] – [f(x) + g(x)] 
h →0 h 
= 
(f(x) + g(x)) ' 
lim [f(x+h) – f(x)] + [g(x+h) – g(x)] 
h h →0 
= 
lim [f(x+h) – f(x)] [g(x+h) – g(x)] 
= + 
h 
h →0 
h 
(the sum property of limits) 
lim [f(x+h) – f(x)] 
h h →0 = + 
lim [g(x+h) – g(x)] 
h →0 
h
Computations of Derivatives 
To verify i, note that 
lim 
[f(x+h) + g(x+h)] – [f(x) + g(x)] 
h →0 h 
= 
(f(x) + g(x)) ' 
lim [f(x+h) – f(x)] + [g(x+h) – g(x)] 
h h →0 
= 
lim [f(x+h) – f(x)] [g(x+h) – g(x)] 
= + 
h 
h →0 
h 
(the sum property of limits) 
lim [f(x+h) – f(x)] 
h h →0 = + 
lim [g(x+h) – g(x)] 
h →0 
h 
= f '(x) + g '(x)
Computations of Derivatives 
To verify i, note that 
lim 
[f(x+h) + g(x+h)] – [f(x) + g(x)] 
h →0 h 
= 
(f(x) + g(x)) ' 
lim [f(x+h) – f(x)] + [g(x+h) – g(x)] 
h h →0 
= 
lim [f(x+h) – f(x)] [g(x+h) – g(x)] 
= + 
h 
h →0 
h 
(the sum property of limits) 
lim [f(x+h) – f(x)] 
h h →0 = + 
lim [g(x+h) – g(x)] 
h →0 
h 
= f '(x) + g '(x) 
Your turn: Verity part ii in a similar manner.
Computations of Derivatives 
Geometrically, (f + g) ' = f ' + g ' says that slope of 
the sum function is the sum of the slopes at any point.
Computations of Derivatives 
Geometrically, (f + g) ' = f ' + g ' says that slope of 
the sum function is the sum of the slopes at any point. 
Let’s illustrate this with graphs.
Computations of Derivatives 
Geometrically, (f + g) ' = f ' + g ' says that slope of 
the sum function is the sum of the slopes at any point. 
Let’s illustrate this with graphs. 
Let the slope at x = a of f(x) be 1/3 
or f '(a) = 1/3 and that 
the slope at x = a of g(x) is 2/3 
or g '(a) = 2/3,
Computations of Derivatives 
Geometrically, (f + g) ' = f ' + g ' says that slope of 
the sum function is the sum of the slopes at any point. 
Let’s illustrate this with graphs. 
Let the slope at x = a of f(x) be 1/3 
or f '(a) = 1/3 and that 
the slope at x = a of g(x) is 2/3 
or g '(a) = 2/3, 
slope = 2/3 
slope = 1/3
Computations of Derivatives 
Geometrically, (f + g) ' = f ' + g ' says that slope of 
the sum function is the sum of the slopes at any point. 
Let’s illustrate this with graphs. 
Let the slope at x = a of f(x) be 1/3 
or f '(a) = 1/3 and that 
the slope at x = a of g(x) is 2/3 
or g '(a) = 2/3, 
then the slope at x = a of (f + g)(x) 
slope = 2/3 
slope = 1/3
Computations of Derivatives 
Geometrically, (f + g) ' = f ' + g ' says that slope of 
the sum function is the sum of the slopes at any point. 
Let’s illustrate this with graphs. 
y=(f + g)(x) 
Let the slope at x = a of f(x) be 1/3 
or f '(a) = 1/3 and that 
the slope at x = a of g(x) is 2/3 
or g '(a) = 2/3, 
then the slope at x = a of (f + g)(x) 
slope = 2/3 
slope = 1/3
Computations of Derivatives 
Geometrically, (f + g) ' = f ' + g ' says that slope of 
the sum function is the sum of the slopes at any point. 
Let’s illustrate this with graphs. 
y=(f + g)(x) 
Let the slope at x = a of f(x) be 1/3 
or f '(a) = 1/3 and that 
the slope at x = a of g(x) is 2/3 
or g '(a) = 2/3, 
then the slope at x = a of (f + g)(x) 
slope = 2/3 
slope = 1/3
Computations of Derivatives 
Geometrically, (f + g) ' = f ' + g ' says that slope of 
the sum function is the sum of the slopes at any point. 
Let’s illustrate this with graphs. 
y=(f + g)(x) 
Let the slope at x = a of f(x) be 1/3 
or f '(a) = 1/3 and that 
the slope at x = a of g(x) is 2/3 
or g '(a) = 2/3, 
then the slope at x = a of (f + g)(x) 
or (f + g)'(a) = 1/3 + 2/3 = 1 
slope 
=1/3+2/3 
= 1 
slope = 2/3 
slope = 1/3
Computations of Derivatives 
Geometrically, (f + g) ' = f ' + g ' says that slope of 
the sum function is the sum of the slopes at any point. 
Let’s illustrate this with graphs. 
y=(f + g)(x) 
Let the slope at x = a of f(x) be 1/3 
or f '(a) = 1/3 and that 
the slope at x = a of g(x) is 2/3 
or g '(a) = 2/3, 
then the slope at x = a of (f + g)(x) 
or (f + g)'(a) = 1/3 + 2/3 = 1 
slope 
=1/3+2/3 
= 1 
slope = 2/3 
slope = 1/3 
Likewise c*f(x) have the slope 
c*f '(x) as the slope at x = a.
Computations of Derivatives 
Geometrically, (f + g) ' = f ' + g ' says that slope of 
the sum function is the sum of the slopes at any point. 
Let’s illustrate this with graphs. 
y=(f + g)(x) 
Let the slope at x = a of f(x) be 1/3 
or f '(a) = 1/3 and that 
the slope at x = a of g(x) is 2/3 
or g '(a) = 2/3, 
then the slope at x = a of (f + g)(x) 
or (f + g)'(a) = 1/3 + 2/3 = 1 
slope 
=1/3+2/3 
= 1 
slope = 2/3 
Likewise c*f(x) have the slope 
c*f '(x) as the slope at x = a. 
The slope of y = 2x – 1 is 2, 
the slope of 3(2x – 1) = 6x – 3 is 6. 
slope = 1/3
Computations of Derivatives 
However the product or quotient rule of limits that 
f 
lim f 
lim (f)(g) = (lim f)*(lim g) and lim 
g = 
lim g 
bear no direct relation for computing derivatives.
Computations of Derivatives 
However the product or quotient rule of limits that 
f 
lim f 
lim (f)(g) = (lim f)*(lim g) and lim 
g = 
lim g 
bear no direct relation for computing derivatives. 
( ) f ' 
fg 
!! (f * g)' ≠ f ' * g ' ≠ g '
Computations of Derivatives 
However the product or quotient rule of limits that 
f 
lim f 
lim (f)(g) = (lim f)*(lim g) and lim 
g = 
lim g 
bear no direct relation for computing derivatives. 
fg 
!! (f * g)' ≠ f ' * g ' ( ) 
≠ g ' 
f ' 
The Product and Quotient Rules of Derivatives
Computations of Derivatives 
However the product or quotient rule of limits that 
f 
lim f 
lim (f)(g) = (lim f)*(lim g) and lim 
g = 
lim g 
bear no direct relation for computing derivatives. 
fg 
!! (f * g)' ≠ f ' * g ' ( ) 
≠ 
f ' 
g ' 
The Product and Quotient Rules of Derivatives 
Write f for f(x) and g for g(x) then 
(fg)' = f'g + fg'
Computations of Derivatives 
However the product or quotient rule of limits that 
f 
lim f 
lim (f)(g) = (lim f)*(lim g) and lim 
g = 
lim g 
bear no direct relation for computing derivatives. 
fg 
!! (f * g)' ≠ f ' * g ' ( ) 
≠ 
f ' 
g ' 
The Product and Quotient Rules of Derivatives 
Write f for f(x) and g for g(x) then 
(fg)' = f'g + fg' 
gf ' – fg' 
g2 
f 
( g)' =
Computations of Derivatives 
However the product or quotient rule of limits that 
f 
lim f 
lim (f)(g) = (lim f)*(lim g) and lim 
g = 
lim g 
bear no direct relation for computing derivatives. 
fg 
!! (f * g)' ≠ f ' * g ' ( ) 
≠ 
f ' 
g ' 
The Product and Quotient Rules of Derivatives 
Write f for f(x) and g for g(x) then 
(fg)' = f'g + fg' 
f 
= 
gf ' – fg' 
( g)' g2 
Here are sites for the verifications of these rules. 
http://en.wikipedia.org/wiki/Product_rule#Proof_of_the_product_rule 
http://en.wikipedia.org/wiki/Quotient_rule
Computations of Derivatives 
Here is a geometric analogy of the Product Rule.
Computations of Derivatives 
Here is a geometric analogy of the Product Rule. 
Given a rectangle of F * G, 
F 
G
Computations of Derivatives 
Here is a geometric analogy of the Product Rule. 
Given a rectangle of F * G, Suppose F is extended to 
F + ΔF and G is extended to G + ΔG 
F 
G
Computations of Derivatives 
Here is a geometric analogy of the Product Rule. 
Given a rectangle of F * G, Suppose F is extended to 
F + ΔF and G is extended to G + ΔG 
F 
G 
ΔF 
ΔG
Computations of Derivatives 
Here is a geometric analogy of the Product Rule. 
Given a rectangle of F * G, Suppose F is extended to 
F + ΔF and G is extended to G + ΔG 
F 
G 
ΔF 
ΔG 
The difference in the two 
areas is 
(F+ΔF)(G+ΔG) – FG
Computations of Derivatives 
Here is a geometric analogy of the Product Rule. 
Given a rectangle of F * G, Suppose F is extended to 
F + ΔF and G is extended to G + ΔG 
F 
G 
ΔF 
ΔG 
The difference in the two 
areas is 
(F+ΔF)(G+ΔG) – FG 
= shaded area
Computations of Derivatives 
Here is a geometric analogy of the Product Rule. 
Given a rectangle of F * G, Suppose F is extended to 
F + ΔF and G is extended to G + ΔG 
F 
G 
ΔF 
ΔG 
The difference in the two 
areas is 
(F+ΔF)(G+ΔG) – FG 
= shaded area 
= three parts
Computations of Derivatives 
Here is a geometric analogy of the Product Rule. 
Given a rectangle of F * G, Suppose F is extended to 
F + ΔF and G is extended to G + ΔG 
F 
G 
ΔF 
ΔG 
The difference in the two 
areas is 
(F+ΔF)(G+ΔG) – FG 
= shaded area 
= three parts 
= F*ΔG F*ΔG
Computations of Derivatives 
Here is a geometric analogy of the Product Rule. 
Given a rectangle of F * G, Suppose F is extended to 
F + ΔF and G is extended to G + ΔG 
F 
G 
ΔF 
ΔG 
The difference in the two 
areas is 
ΔF*G 
(F+ΔF)(G+ΔG) – FG 
= shaded area 
= three parts 
= F*ΔG+ΔF*G F*ΔG
Computations of Derivatives 
Here is a geometric analogy of the Product Rule. 
Given a rectangle of F * G, Suppose F is extended to 
F + ΔF and G is extended to G + ΔG 
F 
G 
ΔF 
ΔG 
The difference in the two 
areas is 
ΔF*G 
(F+ΔF)(G+ΔG) – FG 
= shaded area 
= three parts 
= F*ΔG+ΔF*G+ΔF*ΔG. F*ΔG 
ΔF*ΔG
Computations of Derivatives 
Here is a geometric analogy of the Product Rule. 
Given a rectangle of F * G, Suppose F is extended to 
F + ΔF and G is extended to G + ΔG 
F 
G 
ΔF 
ΔG 
The difference in the two 
areas is 
ΔF*G 
(F+ΔF)(G+ΔG) – FG 
= shaded area 
= three parts 
= F*ΔG+ΔF*G+ΔF*ΔG. F*ΔG 
ΔF*ΔG 
If ΔF and ΔG are small then ΔF*ΔG area is negligible
Computations of Derivatives 
Here is a geometric analogy of the Product Rule. 
Given a rectangle of F * G, Suppose F is extended to 
F + ΔF and G is extended to G + ΔG 
F 
G 
ΔF 
ΔG 
The difference in the two 
areas is 
ΔF*G 
(F+ΔF)(G+ΔG) – FG 
= shaded area 
= three parts 
= F*ΔG+ΔF*G+ΔF*ΔG. F*ΔG 
ΔF*ΔG 
If ΔF and ΔG are small then ΔF*ΔG area is negligible 
so(F+ΔF)(G+ΔG) – FG ≈ F*ΔG+ΔF*G
Computations of Derivatives 
Knowing how the differentiation operation ( ) ' 
interacts with the algebraic operations +, –, *, and /, 
enables us develop the algebra to take the derivatives 
of polynomials and rational functions.
Computations of Derivatives 
Knowing how the differentiation operation ( ) ' 
interacts with the algebraic operations +, –, *, and /, 
enables us develop the algebra to take the derivatives 
of polynomials and rational functions. 
Derivatives of Polynomials and Rational Functions
Computations of Derivatives 
Knowing how the differentiation operation ( ) ' 
interacts with the algebraic operations +, –, *, and /, 
enables us develop the algebra to take the derivatives 
of polynomials and rational functions. 
Derivatives of Polynomials and Rational Functions 
We start with the observations that 
i. If f(x) = c, a constant function, then f '(x) = (c) ' = 0.
Computations of Derivatives 
Knowing how the differentiation operation ( ) ' 
interacts with the algebraic operations +, –, *, and /, 
enables us develop the algebra to take the derivatives 
of polynomials and rational functions. 
Derivatives of Polynomials and Rational Functions 
We start with the observations that 
i. If f(x) = c, a constant function, then f '(x) = (c) ' = 0. 
ii. If f(x) = x, the identity function, then f '(x) = (x) ' = 1.
Computations of Derivatives 
Knowing how the differentiation operation ( ) ' 
interacts with the algebraic operations +, –, *, and /, 
enables us develop the algebra to take the derivatives 
of polynomials and rational functions. 
Derivatives of Polynomials and Rational Functions 
We start with the observations that 
i. If f(x) = c, a constant function, then f '(x) = (c) ' = 0. 
ii. If f(x) = x, the identity function, then f '(x) = (x) ' = 1. 
If we view x2 as the product of f(x)*g(x) where 
f(x) = g(x) = x,
Computations of Derivatives 
Knowing how the differentiation operation ( ) ' 
interacts with the algebraic operations +, –, *, and /, 
enables us develop the algebra to take the derivatives 
of polynomials and rational functions. 
Derivatives of Polynomials and Rational Functions 
We start with the observations that 
i. If f(x) = c, a constant function, then f '(x) = (c) ' = 0. 
ii. If f(x) = x, the identity function, then f '(x) = (x) ' = 1. 
If we view x2 as the product of f(x)*g(x) where 
f(x) = g(x) = x, then 
(x2)' = (fg)’
Computations of Derivatives 
Knowing how the differentiation operation ( ) ' 
interacts with the algebraic operations +, –, *, and /, 
enables us develop the algebra to take the derivatives 
of polynomials and rational functions. 
Derivatives of Polynomials and Rational Functions 
We start with the observations that 
i. If f(x) = c, a constant function, then f '(x) = (c) ' = 0. 
ii. If f(x) = x, the identity function, then f '(x) = (x) ' = 1. 
If we view x2 as the product of f(x)*g(x) where 
f(x) = g(x) = x, then 
(x2)' = (fg)' = (f)'g + f(g)' by the Product Rule
Computations of Derivatives 
Knowing how the differentiation operation ( ) ' 
interacts with the algebraic operations +, –, *, and /, 
enables us develop the algebra to take the derivatives 
of polynomials and rational functions. 
Derivatives of Polynomials and Rational Functions 
We start with the observations that 
i. If f(x) = c, a constant function, then f '(x) = (c) ' = 0. 
ii. If f(x) = x, the identity function, then f '(x) = (x) ' = 1. 
If we view x2 as the product of f(x)*g(x) where 
f(x) = g(x) = x, then 
(x2)' = (fg)' = (f)'g + f(g)' by the Product Rule 
= (1)x + x(1) by the fact (x)' = 1
Computations of Derivatives 
Knowing how the differentiation operation ( ) ' 
interacts with the algebraic operations +, –, *, and /, 
enables us develop the algebra to take the derivatives 
of polynomials and rational functions. 
Derivatives of Polynomials and Rational Functions 
We start with the observations that 
i. If f(x) = c, a constant function, then f '(x) = (c) ' = 0. 
ii. If f(x) = x, the identity function, then f '(x) = (x) ' = 1. 
If we view x2 as the product of f(x)*g(x) where 
f(x) = g(x) = x, then 
(x2)' = (fg)' = (f)'g + f(g)' by the Product Rule 
= (1)x + x(1) by the fact (x)' = 1 
or that (x2)'= 2x
Computations of Derivatives 
Because (x2)' = 2x, therefore the derivative of –2x2 is 
(–2x2)' =
Computations of Derivatives 
Because (x2)' = 2x, therefore the derivative of –2x2 is 
(–2x2)' = –2(x2)' 
We say we “pull out the 
constant “ when we use the 
Constant Multiple Rule.
Computations of Derivatives 
Because (x2)' = 2x, therefore the derivative of –2x2 is 
(–2x2)' = –2(x2)' = –2(2x) = –4x. 
We say we “pull out the 
constant “ when we use the 
Constant Multiple Rule.
Computations of Derivatives 
Because (x2)' = 2x, therefore the derivative of –2x2 is 
(–2x2)' = –2(x2)' = –2(2x) = –4x. 
To calculate 
(–2x2 + 2x + 1)' =
Computations of Derivatives 
Because (x2)' = 2x, therefore the derivative of –2x2 is 
(–2x2)' = –2(x2)' = –2(2x) = –4x. 
To calculate 
“ take derivative 
term by term “ 
(–2x2 + 2x + 1)' = (–2x2)' + (2x)' + (1)'
Computations of Derivatives 
Because (x2)' = 2x, therefore the derivative of –2x2 is 
(–2x2)' = –2(x2)' = –2(2x) = –4x. 
To calculate 
“ take derivative 
term by term “ 
(–2x2 + 2x + 1)' = (–2x2)' + (2x)' + (1)' 
“pull out the constant “ 
= –2(x2)' + 2(x)'
Computations of Derivatives 
Because (x2)' = 2x, therefore the derivative of –2x2 is 
(–2x2)' = –2(x2)' = –2(2x) = –4x. 
To calculate 
(–2x2 + 2x + 1)' = (–2x2)' + (2x)' + (1)' 
“pull out the constant “ 
= –2(x2)' + 2(x)' + 0 
“derivative of constant = 0“ 
“ take derivative 
term by term “
Computations of Derivatives 
Because (x2)' = 2x, therefore the derivative of –2x2 is 
(–2x2)' = –2(x2)' = –2(2x) = –4x. 
To calculate 
“ take derivative 
term by term “ 
(–2x2 + 2x + 1)' = (–2x2)' + (2x)' + (1)' 
“pull out the constant “ 
= –2(x2)' + 2(x)' + 0 
“derivative of constant = 0“ 
= –2(2x) + 2(1)
Computations of Derivatives 
Because (x2)' = 2x, therefore the derivative of –2x2 is 
(–2x2)' = –2(x2)' = –2(2x) = –4x. 
To calculate 
“ take derivative 
term by term “ 
(–2x2 + 2x + 1)' = (–2x2)' + (2x)' + (1)' 
“pull out the constant “ 
= –2(x2)' + 2(x)' + 0 
“derivative of constant = 0“ 
= –2(2x) + 2(1) 
= –4x + 2
Computations of Derivatives 
Because (x2)' = 2x, therefore the derivative of –2x2 is 
(–2x2)' = –2(x2)' = –2(2x) = –4x. 
To calculate 
“ take derivative 
term by term “ 
(–2x2 + 2x + 1)' = (–2x2)' + (2x)' + (1)' 
“pull out the constant “ 
= –2(x2)' + 2(x)' + 0 
“derivative of constant = 0“ 
= –2(2x) + 2(1) 
= –4x + 2 
This method is a lot easier than the limit method 
required by the definition.
Computations of Derivatives 
If we view x3 as the product of f(x)*g(x) where 
f(x) = x2 and g(x) = x,
Computations of Derivatives 
If we view x3 as the product of f(x)*g(x) where 
f(x) = x2 and g(x) = x, then 
(x3)' = (fg)' = (f)'g + f(g)' by the Product Rule
Computations of Derivatives 
If we view x3 as the product of f(x)*g(x) where 
f(x) = x2 and g(x) = x, then 
(x3)' = (fg)' = (f)'g + f(g)' by the Product Rule 
= (x2)'x + x2(x)'
Computations of Derivatives 
If we view x3 as the product of f(x)*g(x) where 
f(x) = x2 and g(x) = x, then 
(x3)' = (fg)' = (f)'g + f(g)' by the Product Rule 
= (x2)'x + x2(x)' = (2x)x + x2(1)
Computations of Derivatives 
If we view x3 as the product of f(x)*g(x) where 
f(x) = x2 and g(x) = x, then 
(x3)' = (fg)' = (f)'g + f(g)' by the Product Rule 
= (x2)'x + x2(x)' = (2x)x + x2(1) 
so (x3)'= 3x2
Computations of Derivatives 
If we view x3 as the product of f(x)*g(x) where 
f(x) = x2 and g(x) = x, then 
(x3)' = (fg)' = (f)'g + f(g)' by the Product Rule 
= (x2)'x + x2(x)' = (2x)x + x2(1) 
so (x3)'= 3x2 
If we view x4 as the product of f(x)*g(x) where 
f(x) = x3 and g(x) = x and apply the result above, 
then we get (x4)' = 4x3.
Computations of Derivatives 
If we view x3 as the product of f(x)*g(x) where 
f(x) = x2 and g(x) = x, then 
(x3)' = (fg)' = (f)'g + f(g)' by the Product Rule 
= (x2)'x + x2(x)' = (2x)x + x2(1) 
so (x3)'= 3x2 
If we view x4 as the product of f(x)*g(x) where 
f(x) = x3 and g(x) = x and apply the result above, 
then we get (x4)' = 4x3. 
Continue in this manner (x5)' = 5x4, (x6)' = 6x5 etc..
Computations of Derivatives 
If we view x3 as the product of f(x)*g(x) where 
f(x) = x2 and g(x) = x, then 
(x3)' = (fg)' = (f)'g + f(g)' by the Product Rule 
= (x2)'x + x2(x)' = (2x)x + x2(1) 
so (x3)'= 3x2 
If we view x4 as the product of f(x)*g(x) where 
f(x) = x3 and g(x) = x and apply the result above, 
then we get (x4)' = 4x3. 
Continue in this manner (x5)' = 5x4, (x6)' = 6x5 etc.. 
we obtain the formula of derivatives of the monomials. 
Derivatives of Monomials 
(xN)' =
Computations of Derivatives 
If we view x3 as the product of f(x)*g(x) where 
f(x) = x2 and g(x) = x, then 
(x3)' = (fg)' = (f)'g + f(g)' by the Product Rule 
= (x2)'x + x2(x)' = (2x)x + x2(1) 
so (x3)'= 3x2 
If we view x4 as the product of f(x)*g(x) where 
f(x) = x3 and g(x) = x and apply the result above, 
then we get (x4)' = 4x3. 
Continue in this manner (x5)' = 5x4, (x6)' = 6x5 etc.. 
we obtain the formula of derivatives of the monomials. 
Derivatives of Monomials 
(xN)' = NxN–1, N = 0, 1, 2, ..
Computations of Derivatives 
If we view x3 as the product of f(x)*g(x) where 
f(x) = x2 and g(x) = x, then 
(x3)' = (fg)' = (f)'g + f(g)' by the Product Rule 
= (x2)'x + x2(x)' = (2x)x + x2(1) 
so (x3)'= 3x2 
If we view x4 as the product of f(x)*g(x) where 
f(x) = x3 and g(x) = x and apply the result above, 
then we get (x4)' = 4x3. 
Continue in this manner (x5)' = 5x4, (x6)' = 6x5 etc.. 
we obtain the formula of derivatives of the monomials. 
Derivatives of Monomials 
(xN)' = NxN–1, N = 0, 1, 2, .. and that (cxN)' = cNxN–1 
where c is a constant.
Computations of Derivatives 
In the 
dxN 
dx 
notation, 
d 
dx 
= NxN–1
Computations of Derivatives 
In the 
dxN 
dx 
notation, 
d 
dx 
= NxN–1 
Example A. Find the derivatives of the following 
functions. 
a. –2x7– πx3 + sin(π/4)x2 + ln(8)
Computations of Derivatives 
In the 
dxN 
dx 
notation, 
d 
dx 
= NxN–1 
Example A. Find the derivatives of the following 
functions. 
a. –2x7– πx3 + sin(π/4)x2 + ln(8) 
(–2x7– πx3 + sin(π/4)x2 + ln(8))'
Computations of Derivatives 
In the 
dxN 
dx 
notation, 
d 
dx 
= NxN–1 
Example A. Find the derivatives of the following 
functions. 
a. –2x7– πx3 + sin(π/4)x2 + ln(8) 
(–2x7– πx3 + sin(π/4)x2 + ln(8))' 
=(–2x7)' – (πx3)' + (sin(π/4)x2)' + (ln(8))'
Computations of Derivatives 
In the 
dxN 
dx 
notation, 
d 
dx 
= NxN–1 
Example A. Find the derivatives of the following 
functions. 
a. –2x7– πx3 + sin(π/4)x2 + ln(8) 
(–2x7– πx3 + sin(π/4)x2 + ln(8))' 
=(–2x7)' – (πx3)' + (sin(π/4)x2)' + (ln(8))' 
= –2 (x7)' –π (x3)' + sin(π/4) (x2)' + 0
Computations of Derivatives 
In the 
dxN 
dx 
notation, 
d 
dx 
= NxN–1 
Example A. Find the derivatives of the following 
functions. 
a. –2x7– πx3 + sin(π/4)x2 + ln(8) 
(–2x7– πx3 + sin(π/4)x2 + ln(8))' 
=(–2x7)' – (πx3)' + (sin(π/4)x2)' + (ln(8))' 
= –2 (x7)' –π (x3)' + sin(π/4) (x2)' + 0 
= –2 (7x6) –π (3x2) + sin(π/4) 2x + 0
Computations of Derivatives 
In the 
dxN 
dx 
notation, 
d 
dx 
= NxN–1 
Example A. Find the derivatives of the following 
functions. 
a. –2x7– πx3 + sin(π/4)x2 + ln(8) 
(–2x7– πx3 + sin(π/4)x2 + ln(8))' 
=(–2x7)' – (πx3)' + (sin(π/4)x2)' + (ln(8))' 
= –2 (x7)' –π (x3)' + sin(π/4) (x2)' + 0 
= –2 (7x6) –π (3x2) + sin(π/4) 2x + 0 
= –14x6 – 3πx2 + (√2/2)2x
Computations of Derivatives 
In the 
dxN 
dx 
notation, 
d 
dx 
= NxN–1 
Example A. Find the derivatives of the following 
functions. 
a. –2x7– πx3 + sin(π/4)x2 + ln(8) 
(–2x7– πx3 + sin(π/4)x2 + ln(8))' 
=(–2x7)' – (πx3)' + (sin(π/4)x2)' + (ln(8))' 
= –2 (x7)' –π (x3)' + sin(π/4) (x2)' + 0 
= –2 (7x6) –π (3x2) + sin(π/4) 2x + 0 
= –14x6 – 3πx2 + (√2/2)2x 
= –14x6 – 3πx2 + x√2
Computations of Derivatives 
b. (–2x2 + 3)(3x + 1)
Computations of Derivatives 
b. (–2x2 + 3)(3x + 1) 
Using the d/dx notation and the Product Rule, 
d(–2x2 + 3)(3x + 1) 
dx 
=
Computations of Derivatives 
b. (–2x2 + 3)(3x + 1) 
Using the d/dx notation and the Product Rule, 
d(–2x2 + 3)(3x + 1) 
dx 
= (–2x2 + 3) d(3x + 1) 
dx + 
d(–2x2 + 3) 
dx 
(3x + 1)
Computations of Derivatives 
b. (–2x2 + 3)(3x + 1) 
Using the d/dx notation and the Product Rule, 
d(–2x2 + 3)(3x + 1) 
dx 
= (–2x2 + 3) d(3x + 1) 
dx + 
d(–2x2 + 3) 
dx 
(3x + 1) 
= (–2x2 + 3)(3 + 0) + (3x + 1)(–4x + 0)
Computations of Derivatives 
b. (–2x2 + 3)(3x + 1) 
Using the d/dx notation and the Product Rule, 
d(–2x2 + 3)(3x + 1) 
dx 
= (–2x2 + 3) d(3x + 1) 
dx + 
d(–2x2 + 3) 
dx 
(3x + 1) 
= (–2x2 + 3)(3 + 0) + (3x + 1)(–4x + 0) 
= –6x2 + 9 –12x2 – 4x
Computations of Derivatives 
b. (–2x2 + 3)(3x + 1) 
Using the d/dx notation and the Product Rule, 
d(–2x2 + 3)(3x + 1) 
dx 
= (–2x2 + 3) d(3x + 1) 
dx + 
d(–2x2 + 3) 
dx 
(3x + 1) 
= (–2x2 + 3)(3 + 0) + (3x + 1)(–4x + 0) 
= –6x2 + 9 –12x2 – 4x 
= –18x2 – 4x + 9
Computations of Derivatives 
b. (–2x2 + 3)(3x + 1) 
Using the d/dx notation and the Product Rule, 
d(–2x2 + 3)(3x + 1) 
dx 
= (–2x2 + 3) d(3x + 1) 
dx + 
d(–2x2 + 3) 
dx 
(3x + 1) 
= (–2x2 + 3)(3 + 0) + (3x + 1)(–4x + 0) 
= –6x2 + 9 –12x2 – 4x 
= –18x2 – 4x + 9 
or that [(–2x2 + 3)(3x + 1)] ' 
= (–6x3 – 2x2 + 9x + 3)'
Computations of Derivatives 
b. (–2x2 + 3)(3x + 1) 
Using the d/dx notation and the Product Rule, 
d(–2x2 + 3)(3x + 1) 
dx 
= (–2x2 + 3) d(3x + 1) 
dx + 
d(–2x2 + 3) 
dx 
(3x + 1) 
= (–2x2 + 3)(3 + 0) + (3x + 1)(–4x + 0) 
= –6x2 + 9 –12x2 – 4x 
= –18x2 – 4x + 9 
or that [(–2x2 + 3)(3x + 1)] ' 
= (–6x3 – 2x2 + 9x + 3)' = –18x2 – 4x + 9
Computations of Derivatives 
c. –2x2 + 3 
3x + 1
Computations of Derivatives 
c. –2x2 + 3 
Use the Quotient Rule 
= 
3x + 1 
–2x2 + 3 
3x + 1 [ ]' 
gf ' – fg' 
g2 
f 
( g )'=
Computations of Derivatives 
c. –2x2 + 3 
= 
3x + 1 
–2x2 + 3 
3x + 1 [ ]' 
(3x + 1)2 
Use the Quotient Rule 
gf ' – fg' 
g2 
f 
( g )'=
Computations of Derivatives 
c. –2x2 + 3 
= 
3x + 1 
–2x2 + 3 
3x + 1 [ ]' 
(3x + 1)(–2x2 + 3)' 
(3x + 1)2 
Use the Quotient Rule 
gf ' – fg' 
g2 
f 
( g )'=
Computations of Derivatives 
c. –2x2 + 3 
= 
3x + 1 
–2x2 + 3 
3x + 1 [ ]' 
(3x + 1)(–2x2 + 3)' – (–2x2 + 3)(3x + 1)' 
(3x + 1)2 
Use the Quotient Rule 
gf ' – fg' 
g2 
f 
( g )'=
Computations of Derivatives 
c. –2x2 + 3 
= 
3x + 1 
–2x2 + 3 
3x + 1 [ ]' 
(3x + 1)(–2x2 + 3)' – (–2x2 + 3)(3x + 1)' 
(3x + 1)2 
Use the Quotient Rule 
gf ' – fg' 
g2 
f 
( g )'= 
(3x + 1)(–4x) – (–2x2 + 3)(3) 
(3x + 1)2 
=
Computations of Derivatives 
c. –2x2 + 3 
= 
3x + 1 
–2x2 + 3 
3x + 1 [ ]' 
(3x + 1)(–2x2 + 3)' – (–2x2 + 3)(3x + 1)' 
(3x + 1)2 
Use the Quotient Rule 
gf ' – fg' 
g2 
f 
( g )'= 
(3x + 1)(–4x) – (–2x2 + 3)(3) 
(3x + 1)2 
= 
–12x2 – 4x + 6x2 – 9 
(3x + 1)2 
=
Computations of Derivatives 
c. –2x2 + 3 
= 
3x + 1 
–2x2 + 3 
3x + 1 [ ]' 
(3x + 1)(–2x2 + 3)' – (–2x2 + 3)(3x + 1)' 
(3x + 1)2 
Use the Quotient Rule 
gf ' – fg' 
g2 
f 
( g )'= 
(3x + 1)(–4x) – (–2x2 + 3)(3) 
(3x + 1)2 
= 
–12x2 – 4x + 6x2 – 9 
(3x + 1)2 
= 
–6x2 – 4x – 9 
(3x + 1)2 
=
More Computations of Derivatives 
The formulas for the derivatives of monomials may 
be extended to the power function f(x) = xP where P is 
any nonzero real number.
More Computations of Derivatives 
The formulas for the derivatives of monomials may 
be extended to the power function f(x) = xP where P is 
any nonzero real number. 
Derivatives of the Power Functions
More Computations of Derivatives 
The formulas for the derivatives of monomials may 
be extended to the power function f(x) = xP where P is 
any nonzero real number. 
Derivatives of the Power Functions 
(xP)' = PxP–1 where P is a non–zero number.
More Computations of Derivatives 
The formulas for the derivatives of monomials may 
be extended to the power function f(x) = xP where P is 
any nonzero real number. 
Derivatives of the Power Functions 
(xP)' = PxP–1 where P is a non–zero number. 
Example B. 
5 
Find the derivative of f(x) = √4x2
More Computations of Derivatives 
The formulas for the derivatives of monomials may 
be extended to the power function f(x) = xP where P is 
any nonzero real number. 
Derivatives of the Power Functions 
(xP)' = PxP–1 where P is a non–zero number. 
Example B. 
5 
Find the derivative of f(x) = √4x2 
5 
(√4x2)' 
= [(4x2)1/5] '
More Computations of Derivatives 
The formulas for the derivatives of monomials may 
be extended to the power function f(x) = xP where P is 
any nonzero real number. 
Derivatives of the Power Functions 
(xP)' = PxP–1 where P is a non–zero number. 
Example B. 
5 
Find the derivative of f(x) = √4x2 
5 
(√4x2)' 
= [(4x2)1/5] ' 
= [41/5x2/5] '
More Computations of Derivatives 
The formulas for the derivatives of monomials may 
be extended to the power function f(x) = xP where P is 
any nonzero real number. 
Derivatives of the Power Functions 
(xP)' = PxP–1 where P is a non–zero number. 
Example B. 
5 
Find the derivative of f(x) = √4x2 
5 
(√4x2)' 
= [(4x2)1/5] ' 
= [41/5x2/5] ' 
= 41/5 [x2/5] '
More Computations of Derivatives 
The formulas for the derivatives of monomials may 
be extended to the power function f(x) = xP where P is 
any nonzero real number. 
Derivatives of the Power Functions 
(xP)' = PxP–1 where P is a non–zero number. 
Example B. 
5 
Find the derivative of f(x) = √4x2 
5 
(√4x2)' 
= [(4x2)1/5] ' 
= [41/5x2/5] ' 
= 41/5 [x2/5] ' 
= 41/5 [ 2 x2/5 – 1] 
5
More Computations of Derivatives 
The formulas for the derivatives of monomials may 
be extended to the power function f(x) = xP where P is 
any nonzero real number. 
Derivatives of the Power Functions 
(xP)' = PxP–1 where P is a non–zero number. 
Example B. 
5 
Find the derivative of f(x) = √4x2 
5 
(√4x2)' 
= [(4x2)1/5] ' 
= [41/5x2/5] ' 
= 41/5 [x2/5] ' 
= 41/5 [ 2 x2/5 – 1] 
5 
(41/5) 
= 2 x –3/5 
5

2.5 computations of derivatives

  • 1.
  • 2.
    Computations of Derivatives The algebra for computing derivatives using the limit approach gets unmanageable fast.
  • 3.
    Computations of Derivatives The algebra for computing derivatives using the limit approach gets unmanageable fast. Elementary functions are built in finitely many steps using a few basic formulas, the real numbers and the algebraic operations +,–, *, / and function composition
  • 4.
    Computations of Derivatives The algebra for computing derivatives using the limit approach gets unmanageable fast. Elementary functions are built in finitely many steps using a few basic formulas, the real numbers and the algebraic operations +,–, *, / and function composition–plug in a formula into another formula.
  • 5.
    Computations of Derivatives The algebra for computing derivatives using the limit approach gets unmanageable fast. Elementary functions are built in finitely many steps using a few basic formulas, the real numbers and the algebraic operations +,–, *, / and function composition–plug in a formula into another formula. It’s because of their structures that elementary functions are the ones we are able to find derivatives easily.
  • 6.
    Computations of Derivatives The algebra for computing derivatives using the limit approach gets unmanageable fast. Elementary functions are built in finitely many steps using a few basic formulas, the real numbers and the algebraic operations +,–, *, / and function composition–plug in a formula into another formula. It’s because of their structures that elementary functions are the ones we are able to find derivatives easily. The operation of taking derivatives is called differentiation.
  • 7.
    Computations of Derivatives The algebra for computing derivatives using the limit approach gets unmanageable fast. Elementary functions are built in finitely many steps using a few basic formulas, the real numbers and the algebraic operations +,–, *, / and function composition–plug in a formula into another formula. It’s because of their structures that elementary functions are the ones we are able to find derivatives easily. The operation of taking derivatives is called differentiation. We will examine how the operation of differentiation behaves under the above operations.
  • 8.
    Computations of Derivatives The following properties of limits pass on directly to the differentiation operation.
  • 9.
    Computations of Derivatives The following properties of limits pass on directly to the differentiation operation. These are the sum, difference, and constant multiplications rules of limits: lim (f ± g) = lim f ± lim g and that lim c(f) = c lim f
  • 10.
    Computations of Derivatives The following properties of limits pass on directly to the differentiation operation. These are the sum, difference, and constant multiplications rules of limits: lim (f ± g) = lim f ± lim g and that lim c(f) = c lim f It’s important to point out here that the corresponding product and quotient properties of limits do not pass on to the differentiation operation.
  • 11.
    Computations of Derivatives The following properties of limits pass on directly to the differentiation operation. These are the sum, difference, and constant multiplications rules of limits: lim (f ± g) = lim f ± lim g and that lim c(f) = c lim f It’s important to point out here that the corresponding product and quotient properties of limits do not pass on to the differentiation operation. The product and quotient rules of differentiation are more complicated.
  • 12.
    Computations of Derivatives The following properties of limits pass on directly to the differentiation operation. These are the sum, difference, and constant multiplications rules of limits: lim (f ± g) = lim f ± lim g and that lim c(f) = c lim f It’s important to point out here that the corresponding product and quotient properties of limits do not pass on to the differentiation operation. The product and quotient rules of differentiation are more complicated. Unless stated otherwise, we assume that the derivatives at x exist in all the theorems below.
  • 13.
    Computations of Derivatives The following properties of limits pass on directly to the differentiation operation. These are the sum, difference, and constant multiplications rules of limits: lim (f ± g) = lim f ± lim g and that lim c(f) = c lim f It’s important to point out here that the corresponding product and quotient properties of limits do not pass on to the differentiation operation. The product and quotient rules of differentiation are more complicated. Unless stated otherwise, we assume that the derivatives at x exist in all the theorems below. The ± and Constant–Multiple Derivative Rules
  • 14.
    Computations of Derivatives The following properties of limits pass on directly to the differentiation operation. These are the sum, difference, and constant multiplications rules of limits: lim (f ± g) = lim f ± lim g and that lim c(f) = c lim f It’s important to point out here that the corresponding product and quotient properties of limits do not pass on to the differentiation operation. The product and quotient rules of differentiation are more complicated. Unless stated otherwise, we assume that the derivatives at x exist in all the theorems below. The ± and Constant–Multiple Derivative Rules Let f(x) and g(x) be two functions then
  • 15.
    Computations of Derivatives The following properties of limits pass on directly to the differentiation operation. These are the sum, difference, and constant multiplications rules of limits: lim (f ± g) = lim f ± lim g and that lim c(f) = c lim f It’s important to point out here that the corresponding product and quotient properties of limits do not pass on to the differentiation operation. The product and quotient rules of differentiation are more complicated. Unless stated otherwise, we assume that the derivatives at x exist in all the theorems below. The ± and Constant–Multiple Derivative Rules Let f(x) and g(x) be two functions then i. (f(x)±g(x)) ' = f '(x)±g '(x) ii. (cf(x)) ' = c*f '(x) where c is a constant.
  • 16.
    Computations of Derivatives To verify i, note that = (f(x) + g(x)) '
  • 17.
    Computations of Derivatives To verify i, note that lim [f(x+h) + g(x+h)] – [f(x) + g(x)] h →0 h = (f(x) + g(x)) '
  • 18.
    Computations of Derivatives To verify i, note that lim [f(x+h) + g(x+h)] – [f(x) + g(x)] h →0 h = (f(x) + g(x)) ' lim [f(x+h) – f(x)] + [g(x+h) – g(x)] h h →0 =
  • 19.
    Computations of Derivatives To verify i, note that lim [f(x+h) + g(x+h)] – [f(x) + g(x)] h →0 h = (f(x) + g(x)) ' lim [f(x+h) – f(x)] + [g(x+h) – g(x)] h h →0 = lim [f(x+h) – f(x)] [g(x+h) – g(x)] = + h h →0 h
  • 20.
    Computations of Derivatives To verify i, note that lim [f(x+h) + g(x+h)] – [f(x) + g(x)] h →0 h = (f(x) + g(x)) ' lim [f(x+h) – f(x)] + [g(x+h) – g(x)] h h →0 = lim [f(x+h) – f(x)] [g(x+h) – g(x)] = + h h →0 h (the sum property of limits) lim [f(x+h) – f(x)] h h →0 = + lim [g(x+h) – g(x)] h →0 h
  • 21.
    Computations of Derivatives To verify i, note that lim [f(x+h) + g(x+h)] – [f(x) + g(x)] h →0 h = (f(x) + g(x)) ' lim [f(x+h) – f(x)] + [g(x+h) – g(x)] h h →0 = lim [f(x+h) – f(x)] [g(x+h) – g(x)] = + h h →0 h (the sum property of limits) lim [f(x+h) – f(x)] h h →0 = + lim [g(x+h) – g(x)] h →0 h = f '(x) + g '(x)
  • 22.
    Computations of Derivatives To verify i, note that lim [f(x+h) + g(x+h)] – [f(x) + g(x)] h →0 h = (f(x) + g(x)) ' lim [f(x+h) – f(x)] + [g(x+h) – g(x)] h h →0 = lim [f(x+h) – f(x)] [g(x+h) – g(x)] = + h h →0 h (the sum property of limits) lim [f(x+h) – f(x)] h h →0 = + lim [g(x+h) – g(x)] h →0 h = f '(x) + g '(x) Your turn: Verity part ii in a similar manner.
  • 23.
    Computations of Derivatives Geometrically, (f + g) ' = f ' + g ' says that slope of the sum function is the sum of the slopes at any point.
  • 24.
    Computations of Derivatives Geometrically, (f + g) ' = f ' + g ' says that slope of the sum function is the sum of the slopes at any point. Let’s illustrate this with graphs.
  • 25.
    Computations of Derivatives Geometrically, (f + g) ' = f ' + g ' says that slope of the sum function is the sum of the slopes at any point. Let’s illustrate this with graphs. Let the slope at x = a of f(x) be 1/3 or f '(a) = 1/3 and that the slope at x = a of g(x) is 2/3 or g '(a) = 2/3,
  • 26.
    Computations of Derivatives Geometrically, (f + g) ' = f ' + g ' says that slope of the sum function is the sum of the slopes at any point. Let’s illustrate this with graphs. Let the slope at x = a of f(x) be 1/3 or f '(a) = 1/3 and that the slope at x = a of g(x) is 2/3 or g '(a) = 2/3, slope = 2/3 slope = 1/3
  • 27.
    Computations of Derivatives Geometrically, (f + g) ' = f ' + g ' says that slope of the sum function is the sum of the slopes at any point. Let’s illustrate this with graphs. Let the slope at x = a of f(x) be 1/3 or f '(a) = 1/3 and that the slope at x = a of g(x) is 2/3 or g '(a) = 2/3, then the slope at x = a of (f + g)(x) slope = 2/3 slope = 1/3
  • 28.
    Computations of Derivatives Geometrically, (f + g) ' = f ' + g ' says that slope of the sum function is the sum of the slopes at any point. Let’s illustrate this with graphs. y=(f + g)(x) Let the slope at x = a of f(x) be 1/3 or f '(a) = 1/3 and that the slope at x = a of g(x) is 2/3 or g '(a) = 2/3, then the slope at x = a of (f + g)(x) slope = 2/3 slope = 1/3
  • 29.
    Computations of Derivatives Geometrically, (f + g) ' = f ' + g ' says that slope of the sum function is the sum of the slopes at any point. Let’s illustrate this with graphs. y=(f + g)(x) Let the slope at x = a of f(x) be 1/3 or f '(a) = 1/3 and that the slope at x = a of g(x) is 2/3 or g '(a) = 2/3, then the slope at x = a of (f + g)(x) slope = 2/3 slope = 1/3
  • 30.
    Computations of Derivatives Geometrically, (f + g) ' = f ' + g ' says that slope of the sum function is the sum of the slopes at any point. Let’s illustrate this with graphs. y=(f + g)(x) Let the slope at x = a of f(x) be 1/3 or f '(a) = 1/3 and that the slope at x = a of g(x) is 2/3 or g '(a) = 2/3, then the slope at x = a of (f + g)(x) or (f + g)'(a) = 1/3 + 2/3 = 1 slope =1/3+2/3 = 1 slope = 2/3 slope = 1/3
  • 31.
    Computations of Derivatives Geometrically, (f + g) ' = f ' + g ' says that slope of the sum function is the sum of the slopes at any point. Let’s illustrate this with graphs. y=(f + g)(x) Let the slope at x = a of f(x) be 1/3 or f '(a) = 1/3 and that the slope at x = a of g(x) is 2/3 or g '(a) = 2/3, then the slope at x = a of (f + g)(x) or (f + g)'(a) = 1/3 + 2/3 = 1 slope =1/3+2/3 = 1 slope = 2/3 slope = 1/3 Likewise c*f(x) have the slope c*f '(x) as the slope at x = a.
  • 32.
    Computations of Derivatives Geometrically, (f + g) ' = f ' + g ' says that slope of the sum function is the sum of the slopes at any point. Let’s illustrate this with graphs. y=(f + g)(x) Let the slope at x = a of f(x) be 1/3 or f '(a) = 1/3 and that the slope at x = a of g(x) is 2/3 or g '(a) = 2/3, then the slope at x = a of (f + g)(x) or (f + g)'(a) = 1/3 + 2/3 = 1 slope =1/3+2/3 = 1 slope = 2/3 Likewise c*f(x) have the slope c*f '(x) as the slope at x = a. The slope of y = 2x – 1 is 2, the slope of 3(2x – 1) = 6x – 3 is 6. slope = 1/3
  • 33.
    Computations of Derivatives However the product or quotient rule of limits that f lim f lim (f)(g) = (lim f)*(lim g) and lim g = lim g bear no direct relation for computing derivatives.
  • 34.
    Computations of Derivatives However the product or quotient rule of limits that f lim f lim (f)(g) = (lim f)*(lim g) and lim g = lim g bear no direct relation for computing derivatives. ( ) f ' fg !! (f * g)' ≠ f ' * g ' ≠ g '
  • 35.
    Computations of Derivatives However the product or quotient rule of limits that f lim f lim (f)(g) = (lim f)*(lim g) and lim g = lim g bear no direct relation for computing derivatives. fg !! (f * g)' ≠ f ' * g ' ( ) ≠ g ' f ' The Product and Quotient Rules of Derivatives
  • 36.
    Computations of Derivatives However the product or quotient rule of limits that f lim f lim (f)(g) = (lim f)*(lim g) and lim g = lim g bear no direct relation for computing derivatives. fg !! (f * g)' ≠ f ' * g ' ( ) ≠ f ' g ' The Product and Quotient Rules of Derivatives Write f for f(x) and g for g(x) then (fg)' = f'g + fg'
  • 37.
    Computations of Derivatives However the product or quotient rule of limits that f lim f lim (f)(g) = (lim f)*(lim g) and lim g = lim g bear no direct relation for computing derivatives. fg !! (f * g)' ≠ f ' * g ' ( ) ≠ f ' g ' The Product and Quotient Rules of Derivatives Write f for f(x) and g for g(x) then (fg)' = f'g + fg' gf ' – fg' g2 f ( g)' =
  • 38.
    Computations of Derivatives However the product or quotient rule of limits that f lim f lim (f)(g) = (lim f)*(lim g) and lim g = lim g bear no direct relation for computing derivatives. fg !! (f * g)' ≠ f ' * g ' ( ) ≠ f ' g ' The Product and Quotient Rules of Derivatives Write f for f(x) and g for g(x) then (fg)' = f'g + fg' f = gf ' – fg' ( g)' g2 Here are sites for the verifications of these rules. http://en.wikipedia.org/wiki/Product_rule#Proof_of_the_product_rule http://en.wikipedia.org/wiki/Quotient_rule
  • 39.
    Computations of Derivatives Here is a geometric analogy of the Product Rule.
  • 40.
    Computations of Derivatives Here is a geometric analogy of the Product Rule. Given a rectangle of F * G, F G
  • 41.
    Computations of Derivatives Here is a geometric analogy of the Product Rule. Given a rectangle of F * G, Suppose F is extended to F + ΔF and G is extended to G + ΔG F G
  • 42.
    Computations of Derivatives Here is a geometric analogy of the Product Rule. Given a rectangle of F * G, Suppose F is extended to F + ΔF and G is extended to G + ΔG F G ΔF ΔG
  • 43.
    Computations of Derivatives Here is a geometric analogy of the Product Rule. Given a rectangle of F * G, Suppose F is extended to F + ΔF and G is extended to G + ΔG F G ΔF ΔG The difference in the two areas is (F+ΔF)(G+ΔG) – FG
  • 44.
    Computations of Derivatives Here is a geometric analogy of the Product Rule. Given a rectangle of F * G, Suppose F is extended to F + ΔF and G is extended to G + ΔG F G ΔF ΔG The difference in the two areas is (F+ΔF)(G+ΔG) – FG = shaded area
  • 45.
    Computations of Derivatives Here is a geometric analogy of the Product Rule. Given a rectangle of F * G, Suppose F is extended to F + ΔF and G is extended to G + ΔG F G ΔF ΔG The difference in the two areas is (F+ΔF)(G+ΔG) – FG = shaded area = three parts
  • 46.
    Computations of Derivatives Here is a geometric analogy of the Product Rule. Given a rectangle of F * G, Suppose F is extended to F + ΔF and G is extended to G + ΔG F G ΔF ΔG The difference in the two areas is (F+ΔF)(G+ΔG) – FG = shaded area = three parts = F*ΔG F*ΔG
  • 47.
    Computations of Derivatives Here is a geometric analogy of the Product Rule. Given a rectangle of F * G, Suppose F is extended to F + ΔF and G is extended to G + ΔG F G ΔF ΔG The difference in the two areas is ΔF*G (F+ΔF)(G+ΔG) – FG = shaded area = three parts = F*ΔG+ΔF*G F*ΔG
  • 48.
    Computations of Derivatives Here is a geometric analogy of the Product Rule. Given a rectangle of F * G, Suppose F is extended to F + ΔF and G is extended to G + ΔG F G ΔF ΔG The difference in the two areas is ΔF*G (F+ΔF)(G+ΔG) – FG = shaded area = three parts = F*ΔG+ΔF*G+ΔF*ΔG. F*ΔG ΔF*ΔG
  • 49.
    Computations of Derivatives Here is a geometric analogy of the Product Rule. Given a rectangle of F * G, Suppose F is extended to F + ΔF and G is extended to G + ΔG F G ΔF ΔG The difference in the two areas is ΔF*G (F+ΔF)(G+ΔG) – FG = shaded area = three parts = F*ΔG+ΔF*G+ΔF*ΔG. F*ΔG ΔF*ΔG If ΔF and ΔG are small then ΔF*ΔG area is negligible
  • 50.
    Computations of Derivatives Here is a geometric analogy of the Product Rule. Given a rectangle of F * G, Suppose F is extended to F + ΔF and G is extended to G + ΔG F G ΔF ΔG The difference in the two areas is ΔF*G (F+ΔF)(G+ΔG) – FG = shaded area = three parts = F*ΔG+ΔF*G+ΔF*ΔG. F*ΔG ΔF*ΔG If ΔF and ΔG are small then ΔF*ΔG area is negligible so(F+ΔF)(G+ΔG) – FG ≈ F*ΔG+ΔF*G
  • 51.
    Computations of Derivatives Knowing how the differentiation operation ( ) ' interacts with the algebraic operations +, –, *, and /, enables us develop the algebra to take the derivatives of polynomials and rational functions.
  • 52.
    Computations of Derivatives Knowing how the differentiation operation ( ) ' interacts with the algebraic operations +, –, *, and /, enables us develop the algebra to take the derivatives of polynomials and rational functions. Derivatives of Polynomials and Rational Functions
  • 53.
    Computations of Derivatives Knowing how the differentiation operation ( ) ' interacts with the algebraic operations +, –, *, and /, enables us develop the algebra to take the derivatives of polynomials and rational functions. Derivatives of Polynomials and Rational Functions We start with the observations that i. If f(x) = c, a constant function, then f '(x) = (c) ' = 0.
  • 54.
    Computations of Derivatives Knowing how the differentiation operation ( ) ' interacts with the algebraic operations +, –, *, and /, enables us develop the algebra to take the derivatives of polynomials and rational functions. Derivatives of Polynomials and Rational Functions We start with the observations that i. If f(x) = c, a constant function, then f '(x) = (c) ' = 0. ii. If f(x) = x, the identity function, then f '(x) = (x) ' = 1.
  • 55.
    Computations of Derivatives Knowing how the differentiation operation ( ) ' interacts with the algebraic operations +, –, *, and /, enables us develop the algebra to take the derivatives of polynomials and rational functions. Derivatives of Polynomials and Rational Functions We start with the observations that i. If f(x) = c, a constant function, then f '(x) = (c) ' = 0. ii. If f(x) = x, the identity function, then f '(x) = (x) ' = 1. If we view x2 as the product of f(x)*g(x) where f(x) = g(x) = x,
  • 56.
    Computations of Derivatives Knowing how the differentiation operation ( ) ' interacts with the algebraic operations +, –, *, and /, enables us develop the algebra to take the derivatives of polynomials and rational functions. Derivatives of Polynomials and Rational Functions We start with the observations that i. If f(x) = c, a constant function, then f '(x) = (c) ' = 0. ii. If f(x) = x, the identity function, then f '(x) = (x) ' = 1. If we view x2 as the product of f(x)*g(x) where f(x) = g(x) = x, then (x2)' = (fg)’
  • 57.
    Computations of Derivatives Knowing how the differentiation operation ( ) ' interacts with the algebraic operations +, –, *, and /, enables us develop the algebra to take the derivatives of polynomials and rational functions. Derivatives of Polynomials and Rational Functions We start with the observations that i. If f(x) = c, a constant function, then f '(x) = (c) ' = 0. ii. If f(x) = x, the identity function, then f '(x) = (x) ' = 1. If we view x2 as the product of f(x)*g(x) where f(x) = g(x) = x, then (x2)' = (fg)' = (f)'g + f(g)' by the Product Rule
  • 58.
    Computations of Derivatives Knowing how the differentiation operation ( ) ' interacts with the algebraic operations +, –, *, and /, enables us develop the algebra to take the derivatives of polynomials and rational functions. Derivatives of Polynomials and Rational Functions We start with the observations that i. If f(x) = c, a constant function, then f '(x) = (c) ' = 0. ii. If f(x) = x, the identity function, then f '(x) = (x) ' = 1. If we view x2 as the product of f(x)*g(x) where f(x) = g(x) = x, then (x2)' = (fg)' = (f)'g + f(g)' by the Product Rule = (1)x + x(1) by the fact (x)' = 1
  • 59.
    Computations of Derivatives Knowing how the differentiation operation ( ) ' interacts with the algebraic operations +, –, *, and /, enables us develop the algebra to take the derivatives of polynomials and rational functions. Derivatives of Polynomials and Rational Functions We start with the observations that i. If f(x) = c, a constant function, then f '(x) = (c) ' = 0. ii. If f(x) = x, the identity function, then f '(x) = (x) ' = 1. If we view x2 as the product of f(x)*g(x) where f(x) = g(x) = x, then (x2)' = (fg)' = (f)'g + f(g)' by the Product Rule = (1)x + x(1) by the fact (x)' = 1 or that (x2)'= 2x
  • 60.
    Computations of Derivatives Because (x2)' = 2x, therefore the derivative of –2x2 is (–2x2)' =
  • 61.
    Computations of Derivatives Because (x2)' = 2x, therefore the derivative of –2x2 is (–2x2)' = –2(x2)' We say we “pull out the constant “ when we use the Constant Multiple Rule.
  • 62.
    Computations of Derivatives Because (x2)' = 2x, therefore the derivative of –2x2 is (–2x2)' = –2(x2)' = –2(2x) = –4x. We say we “pull out the constant “ when we use the Constant Multiple Rule.
  • 63.
    Computations of Derivatives Because (x2)' = 2x, therefore the derivative of –2x2 is (–2x2)' = –2(x2)' = –2(2x) = –4x. To calculate (–2x2 + 2x + 1)' =
  • 64.
    Computations of Derivatives Because (x2)' = 2x, therefore the derivative of –2x2 is (–2x2)' = –2(x2)' = –2(2x) = –4x. To calculate “ take derivative term by term “ (–2x2 + 2x + 1)' = (–2x2)' + (2x)' + (1)'
  • 65.
    Computations of Derivatives Because (x2)' = 2x, therefore the derivative of –2x2 is (–2x2)' = –2(x2)' = –2(2x) = –4x. To calculate “ take derivative term by term “ (–2x2 + 2x + 1)' = (–2x2)' + (2x)' + (1)' “pull out the constant “ = –2(x2)' + 2(x)'
  • 66.
    Computations of Derivatives Because (x2)' = 2x, therefore the derivative of –2x2 is (–2x2)' = –2(x2)' = –2(2x) = –4x. To calculate (–2x2 + 2x + 1)' = (–2x2)' + (2x)' + (1)' “pull out the constant “ = –2(x2)' + 2(x)' + 0 “derivative of constant = 0“ “ take derivative term by term “
  • 67.
    Computations of Derivatives Because (x2)' = 2x, therefore the derivative of –2x2 is (–2x2)' = –2(x2)' = –2(2x) = –4x. To calculate “ take derivative term by term “ (–2x2 + 2x + 1)' = (–2x2)' + (2x)' + (1)' “pull out the constant “ = –2(x2)' + 2(x)' + 0 “derivative of constant = 0“ = –2(2x) + 2(1)
  • 68.
    Computations of Derivatives Because (x2)' = 2x, therefore the derivative of –2x2 is (–2x2)' = –2(x2)' = –2(2x) = –4x. To calculate “ take derivative term by term “ (–2x2 + 2x + 1)' = (–2x2)' + (2x)' + (1)' “pull out the constant “ = –2(x2)' + 2(x)' + 0 “derivative of constant = 0“ = –2(2x) + 2(1) = –4x + 2
  • 69.
    Computations of Derivatives Because (x2)' = 2x, therefore the derivative of –2x2 is (–2x2)' = –2(x2)' = –2(2x) = –4x. To calculate “ take derivative term by term “ (–2x2 + 2x + 1)' = (–2x2)' + (2x)' + (1)' “pull out the constant “ = –2(x2)' + 2(x)' + 0 “derivative of constant = 0“ = –2(2x) + 2(1) = –4x + 2 This method is a lot easier than the limit method required by the definition.
  • 70.
    Computations of Derivatives If we view x3 as the product of f(x)*g(x) where f(x) = x2 and g(x) = x,
  • 71.
    Computations of Derivatives If we view x3 as the product of f(x)*g(x) where f(x) = x2 and g(x) = x, then (x3)' = (fg)' = (f)'g + f(g)' by the Product Rule
  • 72.
    Computations of Derivatives If we view x3 as the product of f(x)*g(x) where f(x) = x2 and g(x) = x, then (x3)' = (fg)' = (f)'g + f(g)' by the Product Rule = (x2)'x + x2(x)'
  • 73.
    Computations of Derivatives If we view x3 as the product of f(x)*g(x) where f(x) = x2 and g(x) = x, then (x3)' = (fg)' = (f)'g + f(g)' by the Product Rule = (x2)'x + x2(x)' = (2x)x + x2(1)
  • 74.
    Computations of Derivatives If we view x3 as the product of f(x)*g(x) where f(x) = x2 and g(x) = x, then (x3)' = (fg)' = (f)'g + f(g)' by the Product Rule = (x2)'x + x2(x)' = (2x)x + x2(1) so (x3)'= 3x2
  • 75.
    Computations of Derivatives If we view x3 as the product of f(x)*g(x) where f(x) = x2 and g(x) = x, then (x3)' = (fg)' = (f)'g + f(g)' by the Product Rule = (x2)'x + x2(x)' = (2x)x + x2(1) so (x3)'= 3x2 If we view x4 as the product of f(x)*g(x) where f(x) = x3 and g(x) = x and apply the result above, then we get (x4)' = 4x3.
  • 76.
    Computations of Derivatives If we view x3 as the product of f(x)*g(x) where f(x) = x2 and g(x) = x, then (x3)' = (fg)' = (f)'g + f(g)' by the Product Rule = (x2)'x + x2(x)' = (2x)x + x2(1) so (x3)'= 3x2 If we view x4 as the product of f(x)*g(x) where f(x) = x3 and g(x) = x and apply the result above, then we get (x4)' = 4x3. Continue in this manner (x5)' = 5x4, (x6)' = 6x5 etc..
  • 77.
    Computations of Derivatives If we view x3 as the product of f(x)*g(x) where f(x) = x2 and g(x) = x, then (x3)' = (fg)' = (f)'g + f(g)' by the Product Rule = (x2)'x + x2(x)' = (2x)x + x2(1) so (x3)'= 3x2 If we view x4 as the product of f(x)*g(x) where f(x) = x3 and g(x) = x and apply the result above, then we get (x4)' = 4x3. Continue in this manner (x5)' = 5x4, (x6)' = 6x5 etc.. we obtain the formula of derivatives of the monomials. Derivatives of Monomials (xN)' =
  • 78.
    Computations of Derivatives If we view x3 as the product of f(x)*g(x) where f(x) = x2 and g(x) = x, then (x3)' = (fg)' = (f)'g + f(g)' by the Product Rule = (x2)'x + x2(x)' = (2x)x + x2(1) so (x3)'= 3x2 If we view x4 as the product of f(x)*g(x) where f(x) = x3 and g(x) = x and apply the result above, then we get (x4)' = 4x3. Continue in this manner (x5)' = 5x4, (x6)' = 6x5 etc.. we obtain the formula of derivatives of the monomials. Derivatives of Monomials (xN)' = NxN–1, N = 0, 1, 2, ..
  • 79.
    Computations of Derivatives If we view x3 as the product of f(x)*g(x) where f(x) = x2 and g(x) = x, then (x3)' = (fg)' = (f)'g + f(g)' by the Product Rule = (x2)'x + x2(x)' = (2x)x + x2(1) so (x3)'= 3x2 If we view x4 as the product of f(x)*g(x) where f(x) = x3 and g(x) = x and apply the result above, then we get (x4)' = 4x3. Continue in this manner (x5)' = 5x4, (x6)' = 6x5 etc.. we obtain the formula of derivatives of the monomials. Derivatives of Monomials (xN)' = NxN–1, N = 0, 1, 2, .. and that (cxN)' = cNxN–1 where c is a constant.
  • 80.
    Computations of Derivatives In the dxN dx notation, d dx = NxN–1
  • 81.
    Computations of Derivatives In the dxN dx notation, d dx = NxN–1 Example A. Find the derivatives of the following functions. a. –2x7– πx3 + sin(π/4)x2 + ln(8)
  • 82.
    Computations of Derivatives In the dxN dx notation, d dx = NxN–1 Example A. Find the derivatives of the following functions. a. –2x7– πx3 + sin(π/4)x2 + ln(8) (–2x7– πx3 + sin(π/4)x2 + ln(8))'
  • 83.
    Computations of Derivatives In the dxN dx notation, d dx = NxN–1 Example A. Find the derivatives of the following functions. a. –2x7– πx3 + sin(π/4)x2 + ln(8) (–2x7– πx3 + sin(π/4)x2 + ln(8))' =(–2x7)' – (πx3)' + (sin(π/4)x2)' + (ln(8))'
  • 84.
    Computations of Derivatives In the dxN dx notation, d dx = NxN–1 Example A. Find the derivatives of the following functions. a. –2x7– πx3 + sin(π/4)x2 + ln(8) (–2x7– πx3 + sin(π/4)x2 + ln(8))' =(–2x7)' – (πx3)' + (sin(π/4)x2)' + (ln(8))' = –2 (x7)' –π (x3)' + sin(π/4) (x2)' + 0
  • 85.
    Computations of Derivatives In the dxN dx notation, d dx = NxN–1 Example A. Find the derivatives of the following functions. a. –2x7– πx3 + sin(π/4)x2 + ln(8) (–2x7– πx3 + sin(π/4)x2 + ln(8))' =(–2x7)' – (πx3)' + (sin(π/4)x2)' + (ln(8))' = –2 (x7)' –π (x3)' + sin(π/4) (x2)' + 0 = –2 (7x6) –π (3x2) + sin(π/4) 2x + 0
  • 86.
    Computations of Derivatives In the dxN dx notation, d dx = NxN–1 Example A. Find the derivatives of the following functions. a. –2x7– πx3 + sin(π/4)x2 + ln(8) (–2x7– πx3 + sin(π/4)x2 + ln(8))' =(–2x7)' – (πx3)' + (sin(π/4)x2)' + (ln(8))' = –2 (x7)' –π (x3)' + sin(π/4) (x2)' + 0 = –2 (7x6) –π (3x2) + sin(π/4) 2x + 0 = –14x6 – 3πx2 + (√2/2)2x
  • 87.
    Computations of Derivatives In the dxN dx notation, d dx = NxN–1 Example A. Find the derivatives of the following functions. a. –2x7– πx3 + sin(π/4)x2 + ln(8) (–2x7– πx3 + sin(π/4)x2 + ln(8))' =(–2x7)' – (πx3)' + (sin(π/4)x2)' + (ln(8))' = –2 (x7)' –π (x3)' + sin(π/4) (x2)' + 0 = –2 (7x6) –π (3x2) + sin(π/4) 2x + 0 = –14x6 – 3πx2 + (√2/2)2x = –14x6 – 3πx2 + x√2
  • 88.
    Computations of Derivatives b. (–2x2 + 3)(3x + 1)
  • 89.
    Computations of Derivatives b. (–2x2 + 3)(3x + 1) Using the d/dx notation and the Product Rule, d(–2x2 + 3)(3x + 1) dx =
  • 90.
    Computations of Derivatives b. (–2x2 + 3)(3x + 1) Using the d/dx notation and the Product Rule, d(–2x2 + 3)(3x + 1) dx = (–2x2 + 3) d(3x + 1) dx + d(–2x2 + 3) dx (3x + 1)
  • 91.
    Computations of Derivatives b. (–2x2 + 3)(3x + 1) Using the d/dx notation and the Product Rule, d(–2x2 + 3)(3x + 1) dx = (–2x2 + 3) d(3x + 1) dx + d(–2x2 + 3) dx (3x + 1) = (–2x2 + 3)(3 + 0) + (3x + 1)(–4x + 0)
  • 92.
    Computations of Derivatives b. (–2x2 + 3)(3x + 1) Using the d/dx notation and the Product Rule, d(–2x2 + 3)(3x + 1) dx = (–2x2 + 3) d(3x + 1) dx + d(–2x2 + 3) dx (3x + 1) = (–2x2 + 3)(3 + 0) + (3x + 1)(–4x + 0) = –6x2 + 9 –12x2 – 4x
  • 93.
    Computations of Derivatives b. (–2x2 + 3)(3x + 1) Using the d/dx notation and the Product Rule, d(–2x2 + 3)(3x + 1) dx = (–2x2 + 3) d(3x + 1) dx + d(–2x2 + 3) dx (3x + 1) = (–2x2 + 3)(3 + 0) + (3x + 1)(–4x + 0) = –6x2 + 9 –12x2 – 4x = –18x2 – 4x + 9
  • 94.
    Computations of Derivatives b. (–2x2 + 3)(3x + 1) Using the d/dx notation and the Product Rule, d(–2x2 + 3)(3x + 1) dx = (–2x2 + 3) d(3x + 1) dx + d(–2x2 + 3) dx (3x + 1) = (–2x2 + 3)(3 + 0) + (3x + 1)(–4x + 0) = –6x2 + 9 –12x2 – 4x = –18x2 – 4x + 9 or that [(–2x2 + 3)(3x + 1)] ' = (–6x3 – 2x2 + 9x + 3)'
  • 95.
    Computations of Derivatives b. (–2x2 + 3)(3x + 1) Using the d/dx notation and the Product Rule, d(–2x2 + 3)(3x + 1) dx = (–2x2 + 3) d(3x + 1) dx + d(–2x2 + 3) dx (3x + 1) = (–2x2 + 3)(3 + 0) + (3x + 1)(–4x + 0) = –6x2 + 9 –12x2 – 4x = –18x2 – 4x + 9 or that [(–2x2 + 3)(3x + 1)] ' = (–6x3 – 2x2 + 9x + 3)' = –18x2 – 4x + 9
  • 96.
    Computations of Derivatives c. –2x2 + 3 3x + 1
  • 97.
    Computations of Derivatives c. –2x2 + 3 Use the Quotient Rule = 3x + 1 –2x2 + 3 3x + 1 [ ]' gf ' – fg' g2 f ( g )'=
  • 98.
    Computations of Derivatives c. –2x2 + 3 = 3x + 1 –2x2 + 3 3x + 1 [ ]' (3x + 1)2 Use the Quotient Rule gf ' – fg' g2 f ( g )'=
  • 99.
    Computations of Derivatives c. –2x2 + 3 = 3x + 1 –2x2 + 3 3x + 1 [ ]' (3x + 1)(–2x2 + 3)' (3x + 1)2 Use the Quotient Rule gf ' – fg' g2 f ( g )'=
  • 100.
    Computations of Derivatives c. –2x2 + 3 = 3x + 1 –2x2 + 3 3x + 1 [ ]' (3x + 1)(–2x2 + 3)' – (–2x2 + 3)(3x + 1)' (3x + 1)2 Use the Quotient Rule gf ' – fg' g2 f ( g )'=
  • 101.
    Computations of Derivatives c. –2x2 + 3 = 3x + 1 –2x2 + 3 3x + 1 [ ]' (3x + 1)(–2x2 + 3)' – (–2x2 + 3)(3x + 1)' (3x + 1)2 Use the Quotient Rule gf ' – fg' g2 f ( g )'= (3x + 1)(–4x) – (–2x2 + 3)(3) (3x + 1)2 =
  • 102.
    Computations of Derivatives c. –2x2 + 3 = 3x + 1 –2x2 + 3 3x + 1 [ ]' (3x + 1)(–2x2 + 3)' – (–2x2 + 3)(3x + 1)' (3x + 1)2 Use the Quotient Rule gf ' – fg' g2 f ( g )'= (3x + 1)(–4x) – (–2x2 + 3)(3) (3x + 1)2 = –12x2 – 4x + 6x2 – 9 (3x + 1)2 =
  • 103.
    Computations of Derivatives c. –2x2 + 3 = 3x + 1 –2x2 + 3 3x + 1 [ ]' (3x + 1)(–2x2 + 3)' – (–2x2 + 3)(3x + 1)' (3x + 1)2 Use the Quotient Rule gf ' – fg' g2 f ( g )'= (3x + 1)(–4x) – (–2x2 + 3)(3) (3x + 1)2 = –12x2 – 4x + 6x2 – 9 (3x + 1)2 = –6x2 – 4x – 9 (3x + 1)2 =
  • 104.
    More Computations ofDerivatives The formulas for the derivatives of monomials may be extended to the power function f(x) = xP where P is any nonzero real number.
  • 105.
    More Computations ofDerivatives The formulas for the derivatives of monomials may be extended to the power function f(x) = xP where P is any nonzero real number. Derivatives of the Power Functions
  • 106.
    More Computations ofDerivatives The formulas for the derivatives of monomials may be extended to the power function f(x) = xP where P is any nonzero real number. Derivatives of the Power Functions (xP)' = PxP–1 where P is a non–zero number.
  • 107.
    More Computations ofDerivatives The formulas for the derivatives of monomials may be extended to the power function f(x) = xP where P is any nonzero real number. Derivatives of the Power Functions (xP)' = PxP–1 where P is a non–zero number. Example B. 5 Find the derivative of f(x) = √4x2
  • 108.
    More Computations ofDerivatives The formulas for the derivatives of monomials may be extended to the power function f(x) = xP where P is any nonzero real number. Derivatives of the Power Functions (xP)' = PxP–1 where P is a non–zero number. Example B. 5 Find the derivative of f(x) = √4x2 5 (√4x2)' = [(4x2)1/5] '
  • 109.
    More Computations ofDerivatives The formulas for the derivatives of monomials may be extended to the power function f(x) = xP where P is any nonzero real number. Derivatives of the Power Functions (xP)' = PxP–1 where P is a non–zero number. Example B. 5 Find the derivative of f(x) = √4x2 5 (√4x2)' = [(4x2)1/5] ' = [41/5x2/5] '
  • 110.
    More Computations ofDerivatives The formulas for the derivatives of monomials may be extended to the power function f(x) = xP where P is any nonzero real number. Derivatives of the Power Functions (xP)' = PxP–1 where P is a non–zero number. Example B. 5 Find the derivative of f(x) = √4x2 5 (√4x2)' = [(4x2)1/5] ' = [41/5x2/5] ' = 41/5 [x2/5] '
  • 111.
    More Computations ofDerivatives The formulas for the derivatives of monomials may be extended to the power function f(x) = xP where P is any nonzero real number. Derivatives of the Power Functions (xP)' = PxP–1 where P is a non–zero number. Example B. 5 Find the derivative of f(x) = √4x2 5 (√4x2)' = [(4x2)1/5] ' = [41/5x2/5] ' = 41/5 [x2/5] ' = 41/5 [ 2 x2/5 – 1] 5
  • 112.
    More Computations ofDerivatives The formulas for the derivatives of monomials may be extended to the power function f(x) = xP where P is any nonzero real number. Derivatives of the Power Functions (xP)' = PxP–1 where P is a non–zero number. Example B. 5 Find the derivative of f(x) = √4x2 5 (√4x2)' = [(4x2)1/5] ' = [41/5x2/5] ' = 41/5 [x2/5] ' = 41/5 [ 2 x2/5 – 1] 5 (41/5) = 2 x –3/5 5