6-2 Solving Quadratic Equations by Graphing

Objectives:Students will be able to

1) Solve quadratic equations by graphing2) Estimate solutions of quadratic equations by

graphing

• A quadratic equation is an equation in the form:

• The solution(s) of a quadratic equation are called the roots of the equation.

• One way to find the roots is to find the zeros of the related quadratic function.

• The zeros of the function are the x-intercepts of the graph.

• Take a look at this graph. What are the zeros?

• The number of solutions of a quadratic equation will depend on how many times the graph crosses the x-axis.

Example 1: Solve each equation by graphing.1)

2)

3)

Try these.4) 5)

• Often, exact roots cannot be found by graphing.

• In this case, you can estimate solutions by stating the consecutive integers between which the roots are located.

Munchkin wants to graph!

Example 2: Solve each equation by graphing. If the exact roots cannot be found, state the executive integers between which the roots are located.1)

Try this.2)