0 is the initial amount and r>0 is the'>

Big Ideas Math Integrated I, 2016
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Big Ideas Math Integrated I, 2016 View details
2. Exponential Growth and Decay
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Exercise 9 Page 286

Recall the general formulas for exponential growth and exponential decay functions.

Initial Amount: 1500
Rate of Growth: 7.4 %
Value of the Function when t=5: ≈ 2143.4

Practice makes perfect
Let's start by recalling the general formulas for exponential growth and exponential decay functions. cc Exponential Growth & Exponential Decay [0.8em] y=a(1+r)^t & y=a(1-r)^t In both cases, a>0 is the initial amount and r>0 is the rate of growth or decay written in decimal form. Moreover, for exponential decay, r is less than 1. Let's rewrite the given function to match one of the above formulas.
f(t)=1500(1.074)^t
f(t)= 1500(1+ 0.074)^t
Our function represents exponential growth, with an initial amount a= 1500 and a rate of growth r= 0.074. To rewrite the rate of growth as a percent, we move the decimal point 2 places to the right. r=0.074 ⇔ r=7.4 % Finally, to evaluate the function when t=5, we will substitute 5 for t in the given formula.
f(t)=1500(1.074)^t
f( 5)=1500(1.074)^5
Evaluate right-hand side
f(5)=1500(1.428964392)
f(5)=2143.446588
f(5)≈ 2143.4