Precalculus: Mathematics for Calculus, 7th Edition

Published by Brooks Cole
ISBN 10: 1305071751
ISBN 13: 978-1-30507-175-9

Chapter 4 - Section 4.2 - The Natural Exponential Function - 4.2 Exercises - Page 342: 27

Answer

(a) $P(0)=100$ (b) $P(10)\approx482$ $P(20)\approx999$ $P(30)\approx1168$ (c) For example, $t=100$ $P(100)\approx1199.99997$ We can clearly see that as the value of $t$ approaches $\infty$ the value of $P(t)$ is getting infinitely close to $1200$. Yes, the graph is perfect visualization of our calculations.

Work Step by Step

According to the information provided, we have: $P(t) = \frac{1200}{1+11e^{-0.2t}}$ (a) To determine initial amount of the population we have to calculate $P(t)$ when $t=0$: $P(0)=\frac{1200}{1+11e^{-0.2\times0}}=\frac{1200}{1+11e^{0}}=\frac{1200}{12}=100$ (b) $t=10$ $P(10)=\frac{1200}{1+11e^{-0.2\times10}}=\frac{1200}{1+11e^{-2}}\approx482.18\approx482$ $t=20$ $P(20)=\frac{1200}{1+11e^{-0.2\times20}}=\frac{1200}{1+11e^{-4}}\approx998.77\approx999$ $t=30$ $P(30)=\frac{1200}{1+11e^{-0.2\times30}}=\frac{1200}{1+11e^{-6}}\approx1168.14\approx1168$ (c) Let's evaluate for $t=100$ $P(100)=\frac{1200}{1+11e^{-0.2\times100}}=\frac{1200}{1+11e^{-20}}\approx1199.99997$ We can clearly see that as the value of $t$ approaches $\infty$ the value of $P(t)$ is getting infinitely close to $1200$. Yes, the graph is perfect visualization of our calculations.
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.