• • • ##### Device
• TI-Nspire™ CX/CX II
• TI-Nspire™ CX CAS/CX II CAS
• TI-Nspire™ Navigator™
• ##### Software

TI-Nspire™ CX
TI-Nspire™ CX CAS

4.5

• ##### Report an Issue

Precalculus: How Cool It Is
by Texas Instruments

#### Objectives

• Students will determine and analyze an exponential model for the temperature of water as it cools.
• Students will make predictions about the time required to reach various water temperatures and about the water temperature at various times.

#### Vocabulary

• exponential function
• regression equation
• sum of squares due to error

#### About the Lesson

This lesson involves creating an exponential regression equation to model the temperature of water as it cools.

As a result, students will:

• Learn how to adjust their equation to produce an equation that will better model the data.
• Adjust their equation to incorporate the fact that water will not get cooler than the temperature of the room..
• Use sliders to change the values of the variables a and b in their model to produce the smallest SSE (the Sum of Squares due to Error) value.