Education Technology

# Activities

• ##### Subject Area

• Math: Algebra I: Quadratic Functions

9-12

60 Minutes

• ##### Device
• TI-83 Plus Family
• TI-84 Plus
• TI-84 Plus Silver Edition

TI Connect™

• ##### Accessories

TI Connectivity Cable

• ##### Other Materials
This is Activity 6 from the EXPLORATIONS Book:
Exploring Mathematics with the CellSheet™ Application

## The Slope of the Tangent Line (Part1)

#### Activity Overview

In this activity, students use the CellSheet™ Application to approximate the slope of a line tangent to a curve.

#### Before the Activity

• Install the CellSheet on the calculator using the TI Connect™, TI-Connectivity cable, and Unit to Unit cables
• See the attached PDF file for detailed instructions for this activity
• Print pages 57 - 62 from the attached PDF file for your class
• #### During the Activity

Distribute the pages to your class.

• Use the quadratic equation for the curve and the x-value of the point of contact of the tangent to find the corresponding y-value
• Set Δx as 1 unit to find another value of x and the corresponding y-value
• Find the slope of the secant line joining the two points
• Use smaller values of Δx (for better approximation of the slope of the tangent line) and determine the slopes of the new secant lines
• Observe the pattern between the Δx values and slopes of the lines
• #### After the Activity

Students will complete the worksheet and answer questions.

Review student results:

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