Graphing Quadratic Functions

By: Rodney Hogan & Bryanna Furlough

What is it?

• Graphing Quadratic Functions is the same as graphing linear equations, but it graphs a line at a curve. You can find things such as how many times the line crosses the x-axis or you can find the zeros.

How To Do It. . . Standard Form

• The equation for standard form is

• Identity a, b, And c. Use the formula for the Axis of Symmetry. Put this “x” value in the equation. This is for the Axis of Symmetry.

• is the formula for Axis of Symmetry.a

b

2

cbxaxy 2

. . .Vertex Form

In order to graphquadratics in vertexform, you must do theequation khxay 2)(and you have to take the opposite of “h” and take the “k” value and that’s your vertex. So in other words your vertex is (-h, k)

Example # 1

212

4

2

a

b 9

4

1

c

b

a942 xxy

Do a

b

2

139)2(4)2( 2 yPlug it in

)13,2(

Axis of Symmetry

Vertex

Video For Extra Help

Pawz refers back to example one so make sure you check back at that to

understand what he is saying.

Click Here For Pawz To Show You How To Graph Quadratic Functions

Example Problems

32.1 2 xxy

42.2 xxy

463.3 2 xxy

156.4 2 xxy

74.5 2 xxy

22 289.6 xxxy

2.7 2 xy

163.8 2 xxy

34.9 2 xxy

1)2(.10 2 xy

Answers on next slide

Answers

• (2,11)• (2,12)• (1,1)• (-3,42)• (-2,3)• (2,1)• (0,2)• (1,-4)• (2,-1)• (2,1)

Graphing For Example Problems

1. 2. 3.

4. 5. 6.

Continued. .

7. 8. 9.

10.

More Resources

If you need more help, you can do these things:

Quiz: http://quiz.econ.usyd.edu.au/mathquiz/quadratics/quiz1.php

Game: http://www.quia.com/cb/24731.htmlMore Information:http://www.wtamu.edu/academic/anns/mps/math/

mathlab/col_algebra/col_alg_tut34_quadfun.htm http://www.purplemath.com/modules/grphquad.htm

http://www.analyzemath.com/Graphing/GraphingQuadraticFunction.html