Name:
Period: _____
Date: ______________
8-5 Solving Quadratic Equations by Graphing
Quadratic Equation:
Standard form for Quadratic Functions:
Standard form for Quadratic Equations:
What does it mean to solve a quadratic equation?
Method 1 for Solving Quadratic Equations- Graphing
1) Write the related function
2) Graph the related function
3) Find the zeros of the related function
Example #1Related function:
Graph the functionAxis of Symmetry:
Vertex:
Two other points:
What is the solution(s) to the equation?
How many solutions can an quadratic equation have? (think of the graph)
Solve each quadratic equation by graphing the related function and finding the zeros.
1) x 2  4x  4  0
3) x 2  1
2) x 2  x  6
4) 7  x 2  3x
5) Gretchen throws a ball straight up in the air. The quadratic function y  16x 2  48x models the
height in feet of the ball after x seconds. Use a graphing calculator to sketch the graph of this
function. Use the zeros to find how long the ball is in the air.