# Activities

• • • ##### Subject Area

• Math: Precalculus: Parametric Equations

• ##### Author 9-12

60 Minutes

• ##### Software

TI InterActive!™

• ##### Other Materials
This is Activity 1 from the EXPLORATIONS Book:
TI InterActive! Math for High School

• ##### Report an Issue

Investigating Slope and Y-Intercept

#### Activity Overview

In this activity, students investigate the effect of change in parameters m (slope), and b (y-intercept) on the graph of the equation y = mx + b.

#### Before the Activity

• See the attached PDF file for detailed instructions for this activity
• Print pages 1 - 7 from the attached PDF file for your class
• #### During the Activity

Distribute the pages to the class.

• Graph the equation y = mx for m = 1
• Change value of slope m to 2, 3, and 4, and graph the equations
• Observe that greater the value of m, the steeper the graph
• Change value of m to 1/2, 1/3, and 1/4 and sketch the graph of the lines
• Observe that as the value of m becomes smaller the graph becomes less steep
• Change slope value to -1, -2, and -1/2 and graph the lines
• Note that graphs with negative slopes all decrease as x increases and as the value of m approaches zero, the graph becomes less steep
• Change y-intercept to 2, -1, and 5 and graph the lines
• Observe that the y-intercepts and the value of b are the same
• #### After the Activity

Students complete the Analysis questions.

Review student results:

• As a class, discuss questions that appeared to be more challenging
• Re-teach concepts as necessary