SOLVING QUADRATIC EQUATIONS
USING THE QUADRATIC FORMULA
April 15, 2014
# 27. Change equation to the one on the board.
You now possess 5 methods to solve
quadratic equations. They are:
C) Finding square roots
B) Completing the square
D) Crea...
**She’s beautiful, and she’s all yours
The Quadratic Formula:
THE QUADRATIC FORMULA
.....Solves every quadratic equation, making ‘unsolvable’
a thing of the past.
Imaginary numbers are...
Solve the equation with the Quadratic Formula
2x2 – 5x – 3 = 0
The first thing we need to do is to see if
this fits the fi...
EXAMPLE 1
x = 5 + 7
4
x = 12
4
x = 5 - 7
4
x = -2
4
x = 3
x = -1/2
Rearrange to standard form first
EXAMPLE 2
Solve 2x2 + 7x = 9
2x2 + 7x – 9 = 0
Identify the a, b & c and plug them in.
2x2...
Now we identify the a, b & c and
place it in formula two. Then we
solve.
x = -(7) ± √(7)2 – 4(2)(-9)
2(2)
x = -7 ± √49 – (...
x = -7 ± 11
4
x = 4
4
x = 1
x = -9/2
EXAMPLE 2
x = -7 - 11
4
x = -18
4
x = -7 + 11
4
x = -(1) ± √(1)2 – 4(1)(-1)
2(1)
LAST EXAMPLE
Solve x2 + x – 1 = 0
First we need to identify a, b & c
PROBLEM 3
x = -(1) ± √(1)2 – 4(1)(-1)
2(1)
We can go no further since 5
can’t be squared.
x = -1 + √5
2
x = -1 - √5
2
LAST...
COMPLETE & SUBMIT CLASS
WORK TODAY!
Upcoming SlideShare
Loading in …5
×

April 15, 2014

633 views

Published on

Published in: Technology
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
633
On SlideShare
0
From Embeds
0
Number of Embeds
404
Actions
Shares
0
Downloads
17
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

April 15, 2014

  1. 1. SOLVING QUADRATIC EQUATIONS USING THE QUADRATIC FORMULA April 15, 2014
  2. 2. # 27. Change equation to the one on the board.
  3. 3. You now possess 5 methods to solve quadratic equations. They are: C) Finding square roots B) Completing the square D) Creating a table of x/y values A) Factoring And thus, it is time. You have proven yourself and are ready for the awesome responsibility awaiting you.. You are about to acquire the ultimate weapon in your battle to slay the quadratic dragon. Ladies & Gentlemen, the nuclear option, the peace maker, the final solution... Beware though, it is wild and not easily tamed. E) Graphing
  4. 4. **She’s beautiful, and she’s all yours The Quadratic Formula:
  5. 5. THE QUADRATIC FORMULA .....Solves every quadratic equation, making ‘unsolvable’ a thing of the past. Imaginary numbers are not covered until Algebra 2. This means that we still may have some equations that are unsolvable to us. Pro’s Cons No figuring out what method to use Formula must be memorized If used every time, solving will be easier and faster Must always be aware of signs and order of operations
  6. 6. Solve the equation with the Quadratic Formula 2x2 – 5x – 3 = 0 The first thing we need to do is to see if this fits the first formula. It does since it has the variable squared, the coefficient and the constant all equaling to zero. Next we find the a, b & c and put them into the second formula. a = 2 b = -5 c = -3
  7. 7. EXAMPLE 1 x = 5 + 7 4 x = 12 4 x = 5 - 7 4 x = -2 4 x = 3 x = -1/2
  8. 8. Rearrange to standard form first EXAMPLE 2 Solve 2x2 + 7x = 9 2x2 + 7x – 9 = 0 Identify the a, b & c and plug them in. 2x2 + 7x – 9 = 0
  9. 9. Now we identify the a, b & c and place it in formula two. Then we solve. x = -(7) ± √(7)2 – 4(2)(-9) 2(2) x = -7 ± √49 – (- 72) 4 x = -7 ± √121 4 x = -7 ± 11 4 EXAMPLE 2
  10. 10. x = -7 ± 11 4 x = 4 4 x = 1 x = -9/2 EXAMPLE 2 x = -7 - 11 4 x = -18 4 x = -7 + 11 4
  11. 11. x = -(1) ± √(1)2 – 4(1)(-1) 2(1) LAST EXAMPLE Solve x2 + x – 1 = 0 First we need to identify a, b & c
  12. 12. PROBLEM 3 x = -(1) ± √(1)2 – 4(1)(-1) 2(1) We can go no further since 5 can’t be squared. x = -1 + √5 2 x = -1 - √5 2 LAST EXAMPLE x = -1 ± √5 2 x = -1 ± √1+ 4 2
  13. 13. COMPLETE & SUBMIT CLASS WORK TODAY!

×