Quadratic Formula Presentation
-
Upload
anjuli1580 -
Category
Education
-
view
4.605 -
download
0
Transcript of Quadratic Formula Presentation
QUADRATIC FORMULA
2 WAYS TO SOLVE QUADRATIC EQUATIONS
Factoring(x )(x ) = 0
Graphing
But, what if factoring and graphing are not possible??
EXAMPLE #12x2 – 4x – 3 = 0
* can not be factored: (2x )(x )* can not easily be graphed for a solution:
X 2x2 – 4x – 3 = 0
0 -3
1 -5
-1 -1
EXAMPLE #2x2 – 4x – 8 = 0
* can not be factored: (x )(x )* can not easily be graphed for a solution:
X x2 – 4x – 8 = 0
0 -8
1 -11
-1 -3
WHAT DO WE DO??
We use the
QUADRATIC FORMULA
2a4ac2bbx
THE DIFFERENT PARTS OF THE QUADRATIC FORMULA
Standard Form of a Quadratic Equation:ax2 + bx + c = 0
Let’s look at Example #1 to identifythe different parts:
2x2 – 4x – 3 = 0
ax2 + bx + c = 0
a = 2 b = -4 c = -3
LET’S DO EXAMPLE #1
a = 2 b = -4 c = -3
2a4ac2bbx
210±2=x
4102±4=x
440±4=x
424+16±4=x
2(2)(4)(2)(-3)-2(-4)±4=x
2x2 – 4x – 3 = 0
NOW YOU TRY A PROBLEM
a = 2 b = -1 c = -6
2a4ac2bbx -±-=
23-2,=x
47±1=x4
49±1=x
448+1±1=x
2(2)(4)(2)(-6)- 21±1=x
2x2 – x – 6 = 0
SOME PROBLEMS REQUIRE US TO REWRITE THEM IN STANDARD FORM
FIRST
a = 1 b = -4 c = -8
2a4ac2bbx
32±2=x2
34±4=x
248±4=x
232+16±4=x
2(1)(4)(1)(-8)-2(-4)±4=x
x2 – 4x = 8 Rewrite in standard form x2 – 4x - 8 = 0
NOW YOU TRY A PROBLEM
a = 2 b = 5 c = -10
2a4ac2bbx
2x2 = -5x +10 2x2 + 5x – 10Rewrite in standard form
4105±5-=x
480+25±5-=x
2(2))(4)(2)(-10-2(5)±5-=x
HOW ABOUT YOU TRY SOME PROBLEMS ON YOUR OWN NOW…
Try the QUADRATIC FORMULA WORKSHEET QUADRATIC FORMULA WORKSHEET
and then see me to check your answers
LET’S LISTEN TO THAT SONG AGAIN!
2a4ac2bbx
ANY QUESTIONS???
SOME VERSIONS OF THE QUADRATIC FORMULA SONG:http://www.youtube.com/watch?v=U7q5fgGyqxk
http://www.youtube.com/watch?v=D_0vgqi7fU4