For more information or for a trial version of TI InterActive!™ click here
This is Activity 6 from the EXPLORATIONS Book: TI InterActive! Math for High School

In this activity, students explore the standard form of a quadratic equation, y = ax ^{2} + bx + c. They explore how the x-intercepts (zeros), y-intercept, and vertex are related to the graph of the standard form of a quadratic function.

Before the Activity

See the attached PDF file for detailed instructions for this activity

Print pages 49 - 53 from the attached PDF file for your class

During the Activity

Distribute the pages to the class.

Follow the Activity procedures:

Define and graph a quadratic equation

Determine the values of the x-intercepts

Observe that these are the points where the graph crosses the x-axis

Determine the value of the y-intercept

Observe that this is the point where the graph crosses the y-axis

Determine the coordinates of the vertex, the point with the lowest value of y

Find the value of y for x = -4, -1, 0, and 2

Find the zeros and factors of the expression

Find the zeros of the factors

Observe that the zeros of each factor and zeros of the function are the same, and also the zeros of the function and the x-intercept are the same

Observe that the x-intercepts can be found without graphing, by first finding the factors, and then finding their zeros

Observe that the value of y when x = 0 and the y-intercept are the same

After the Activity

Students complete the Student Activity sheet.

Review student results:

As a class, discuss questions that appeared to be more challenging