Students will explore the effect the coefficient of x^2 has on the graph of a quadratic function; they will also explore the effect of adding a constant to the quadratic function.
Before the Activity
Give each student an index card with a quadratic function in the form y = ax^2 and one equation in the form y = ax^2 + c. Configure Activitiy Center for students to send in one equation.
During the Activity
Students need to be logged on and in Activity Center.
Ask students to send in the first equation on their index card. After all students have sent their equation, stop the activity and direct their attention to the shapes of the graph. Click on "Show student names". Click on "Equation/Graph" to show which equation produced each graph. Guide students to see that the larger the coefficient of x^2 the "tighter" the graph and the smaller the coefficient of x^2 the "wider" the graph. Repeat activity with the second equation on the index card. Guide students to see that the constant moves the y-intercept up and down.