Question

Determine whether the equation represents an exponential growth function, anexponential decay function, and give the percent growth or decay.17. y = 18(1.3)^t

Answer 1

A exponential growth or decay function has the next general form:

`y=a(1\pm r)^t`

If it is :

(1+r) , (>1) the function growth

(1-r) , (<1) the function decay

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The given equation:

`y=18(1.3)^t`As the (1+r) is equal to 1.3 (> 1) then it is a exponential growth function.

In (1+r) the r is the percent of growth, then for the given equation you have:

`\begin{gathered} 1+r=1.3 \\ r=1.3-1 \\ \\ r=0.3 \end{gathered}`The percent of decay is 0.3 or 30%