An introduction to
Integration
The inverse process of
Differentiation
IB SL/HL
The inverse of differentiation
f (x) = 4x3
+ 6x2
Notation for integration.
Integration is the opposite of
differentiation.
4x3
+ 6x2
( )dx∫
Integrate with respect to x.
4x3
+ 6x2
( )dx∫ =
4x4
4
+
6x3
3
= x4
+ 2x3
Add one to the power and divide
by the new power.
Now differentiate and we should
return to f(x).
Also if we take a function,
differentiate it and then integrate
it we will return to the original
function.
For each of the functions below
differentiate and then integrate
with respect to x.
1. f (x) = 3x2
− 8x + 5
2. g(x) =10x4
− 3x2
+ 4x −10
3. h(x) =
4
x
+12x3
− y
What conclusions can you draw?
Integration
This is called indefinite integration.
The formula for this is:
xn
dx =
xn+1
n +1
+ C, n ≠ −1∫
Integration questions
Questions Answers
Integration questions
Questions Answers
sin x( )dx∫ = −cosx + c
4x2
+ 5x −1( )dx∫ =
4x3
3
+
5x2
2
− x + c
cos x( )dx∫ = sin x + c
ex
( )dx∫ = ex
+ c
Multiples
6x3
− 3x2
+12x + 9( )dx∫
can be re-written as,
now it becomes easier to
integrate,
3 2x3
− x2
+ 4x + 3( )dx =∫
3 2x3
− x2
+ 4x + 3( )dx∫
Questions
1. −3sin x( )dx∫
3. 10x2
− 20x3
+ 25x4
( )dx∫
3cosx + c
4ln x + c
10x3
3
− 5x4
+ 5x5
+ c
Finding the c value
y = x3
+ 2x2
− 4x + c
(1,4) 4 = (1)3
+ 2(1)2
− 4(1) + c
c = 5
y = x3
+ 2x2
− 4x + 5
Questions
Find f(x) for each of the following.
Finding the c value
y = x3
+ 2x2
− 4x + c
(1,4) 4 = (1)3
+ 2(1)2
− 4(1) + c
c = 5
y = x3
+ 2x2
− 4x + 5
Questions
Find f(x) for each of the following.
f (x) =
x2
2
+ 3x −1
f (x) = 3cos x + 2
f (x) = 5ln x + x − 3

Lesson 1 integration as the inverse of differentiation

  • 1.
    An introduction to Integration Theinverse process of Differentiation IB SL/HL
  • 2.
    The inverse ofdifferentiation f (x) = 4x3 + 6x2 Notation for integration. Integration is the opposite of differentiation. 4x3 + 6x2 ( )dx∫ Integrate with respect to x. 4x3 + 6x2 ( )dx∫ = 4x4 4 + 6x3 3 = x4 + 2x3 Add one to the power and divide by the new power. Now differentiate and we should return to f(x). Also if we take a function, differentiate it and then integrate it we will return to the original function. For each of the functions below differentiate and then integrate with respect to x. 1. f (x) = 3x2 − 8x + 5 2. g(x) =10x4 − 3x2 + 4x −10 3. h(x) = 4 x +12x3 − y What conclusions can you draw?
  • 3.
    Integration This is calledindefinite integration. The formula for this is: xn dx = xn+1 n +1 + C, n ≠ −1∫
  • 4.
  • 5.
    Integration questions Questions Answers sinx( )dx∫ = −cosx + c 4x2 + 5x −1( )dx∫ = 4x3 3 + 5x2 2 − x + c cos x( )dx∫ = sin x + c ex ( )dx∫ = ex + c
  • 6.
    Multiples 6x3 − 3x2 +12x +9( )dx∫ can be re-written as, now it becomes easier to integrate, 3 2x3 − x2 + 4x + 3( )dx =∫ 3 2x3 − x2 + 4x + 3( )dx∫ Questions 1. −3sin x( )dx∫ 3. 10x2 − 20x3 + 25x4 ( )dx∫ 3cosx + c 4ln x + c 10x3 3 − 5x4 + 5x5 + c
  • 7.
    Finding the cvalue y = x3 + 2x2 − 4x + c (1,4) 4 = (1)3 + 2(1)2 − 4(1) + c c = 5 y = x3 + 2x2 − 4x + 5 Questions Find f(x) for each of the following.
  • 8.
    Finding the cvalue y = x3 + 2x2 − 4x + c (1,4) 4 = (1)3 + 2(1)2 − 4(1) + c c = 5 y = x3 + 2x2 − 4x + 5 Questions Find f(x) for each of the following. f (x) = x2 2 + 3x −1 f (x) = 3cos x + 2 f (x) = 5ln x + x − 3