# Activities

• • • ##### Subject Area

• Math: Algebra I: Linear Functions
• Math: Developmental Mathematics - College: Graphs and Linear Functions

• ##### Author 9-12

45 Minutes

• ##### Device
• TI-Nspire™
• TI-Nspire™ CAS
• ##### Software

TI-Nspire™
TI-Nspire™ CAS

• ##### Report an Issue

Find the Equation of the Line

#### Activity Overview

Teachers and/or students will look at given information (two points, a point and a slope, a point and a parallel line, and a point and a perpendicular line) and have to find the linear function that works. As the activity is occuring on the calculator, the students have a worksheet to record their information. They should know from testing their solution whether or not their answer works.

#### Before the Activity

Prior to this activity, students should have a basic understanding of slope and points. They should know their slope formulas and how various types of lines change according to the slope.

#### During the Activity

This activity can be done either by the teacher modeling and using student input or by downloading the .tns file to the individual calculators and having students try on their own.
Either way, the activity is intended to help students practice writing linear functions and then testing their answers to see if they work. If their solution failed to meet the criteria, then they need to reevaluate their answer to see where they went wrong. Was it the right slope? Was the y-intercept in the right place?

#### After the Activity

After the activity, if the teacher wants to visit the idea of perpendicular lines, the student can use TI-Nspire™ to measure the angle between the equation of the line they wrote and the exisiting line to see if it makes a 90 degree angle.
The teacher can also expand on this lesson with vertical lines, since the student is unable to graph those using the calculator.