Education Technology

Precalculus: How Cool It Is

by Texas Instruments


  • 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.


  • 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.