5.5.0 Lesson Overview

In this lesson, you will work more with growth factors. You will continue to write equations and interpret graphs as you learn about exponential decay.

When you finish this lesson, you will be able to:

• Use only multiplication to represent “decreasing a quantity by a fraction of itself.”
• Write an expression or equation to represent a quantity that decays exponentially.
• Know the meanings of “exponential growth” and “exponential decay.”
• Explain the meanings of $a$ and $b$ in an equation that represents exponential decay and is written as $y=a·b^x$.
• Find a growth factor from a graph and write an equation to represent exponential decay.
• Graph equations that represent quantities that change by a growth factor between 0 and 1.

Here are the activities that will help you reach those goals:

• 5.5.1: Identifying Linear and Exponential Quantities
• 5.5.2: Exponential Decay 
  • 5.5.2: Self Check
  • 5.5.2: Additional Resources
• 5.5.3: Using Graphs to Represent Exponential Decay
  • 5.5.3: Self Check
  • 5.5.3: Additional Resources
• 5.5.4: Justifying Exponential Models
  • 5.5.4: Self Check
  • 5.5.4: Additional Resources
• 5.5.5: Writing Equations to Represent Exponential Decay 

After that, you’ll practice and review.

• 5.5.6: Practice
• 5.5.7: Lesson Summary