Big Ideas Math Algebra 1, 2015
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Big Ideas Math Algebra 1, 2015 View details
4. Exponential Growth and Decay
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Exercise 11 Page 319

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

Initial Amount: 6.72
Rate of Growth: 100 %
Value When t=5: ≈ 215.0

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 growth r is more than 1. Let's rewrite the given function to match one of the above formulas.
g(t)=6.72(2)^t
g(t)= 6.72(1+ 1)^t
Our function represents exponential growth, with an initial amount a= 6.72 and a rate of growth r= 1. To rewrite the rate of growth as a percent, we move the decimal point 2 places to the right. r=1 ⇔ r=100 % Finally, to evaluate the function when t=5 we will substitute 5 for t in the given formula.
g(t)=6.72(2)^t
g( 5)=6.72(2)^5
Evaluate right-hand side
g(5)=6.72(32)
g(5)=215.04
g(5)≈ 215.0