Precalculus 2014
34

 PAGE: 167 SET: Exercises PROBLEM: 34

If an initial quantity grove or decays at an exponential rate or , then the final amount after a time is given by the following formula .

(a)

Find exponential equation for .

Growth rate of inflation between and .

So the time period is .

CPI in was   and was .

Substitute  , and in .

.

Exponential equation is .

(b)

Find the CPI in .

Growth rate of inflation between and .

So the time period is .

.

Find when CPI exceeds 350.

Apply logarithm on each side.

.

CPI exceeds after years, so CPI exceeds after  .

(a) Exponential equation is .

(b)

CPI in is .

CPI exceeds after  years.

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