Growth or Decay? Exponential decay Percent Rate of Change: 40 %
Practice makes perfect
Let's start by recalling the general formula of exponential growth and exponential decay functions.
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Exponential Growth & Exponential Decay [0.8em]
y=a(1+r)^t & y=a(1-r)^tIn both cases, a and r are positive numbers. For exponential decay, r is less than 1. Let's rewrite the given function to match one of the above formulas.
Our function matches the format of exponential decay. Here a= 80 and r= 0.4.
y= 80(1- 0.4)^t
This means that the rate of decay, also known as the percent of change, is 40 %.
