Question

A a population shrinks from its initial level of 24,000 at a continuous decay rate of 5.9% per year.
(a) Find a formula for P(t), the population in t years.
(b) By what percent does the population shrink each year?

I found the formula: P=24,000e^(-0.059t) for (a) but I have no idea how to find (b)

Answer 1

@ganeshie8 you can explain here if its easier

Answer 2

http://www.wolframalpha.com/input/?i=e%5E%28-0.059%29-1

Answer 3

^^interpret that

Answer 4

I get where you get the e^0.059 but I don't understand why you multiplied it by -1

Answer 5

Okay, try this :

Population in the start = 24,000
Population after one year = 24,000e^(-0.059(1)) = 24,000e^(-0.059)

Answer 6

evaluate them both, and find the difference

Answer 7

that tells you how many ppl (population) decayed/dead in first year

Answer 8

difference = 24,000e^(-0.059) - 24,000
= 24,000(e^(-0.059) -1 )

Answer 9

divide it by the start amount to get the percent change

Answer 10

24,000(e^(-0.059) -1 )
------------------ = e^(-0.059) - 1
24000

Answer 11

oh okay that makes more sense. In wolfram it looked like you were doing e^(-.0.059*-1) and I didn't understand

Answer 12

ahh wolfram is somhow making it in unreadable format lol
http://www.wolframalpha.com/input/?i=%28e%5E%28-0.059%29%29++-+++1

Answer 13

lol yeah wolfram can be touchy. but it makes sense just fine without it. I do get it now

Answer 14

good :)