University Calculus: Early Transcendentals (3rd Edition)

Published by Pearson
ISBN 10: 0321999584
ISBN 13: 978-0-32199-958-0

Chapter 4 - Section 4.1 - Extreme Values of Functions - Exercises - Page 215: 40

Answer

$g(x)$ has the absolute maximum value of $1$ at $x=0$ and the absolute minimum value of $e^{-4}$ at $x=-2$.

Work Step by Step

$$g(x)=e^{-x^2}\hspace{1cm}-2\le x\le1$$ 1) Find the critical points of $g(x)$ Find $g'(x)$: $$g'(x)=e^{-x^2}(-x^2)'$$ $$g'(x)=-2xe^{-x^2}$$ Since $e^{-x^2}\gt0$ for all $x\in R$, we have $g(x)=0$ when $x=0$. There are no values of $x$ where $g(x)$ is undefined. So $x=0$ is the critical point of $g(x)$. And since $0\in[-2,1]$, we need to consider it here. 2) Evaluate $g(x)$ at the critical points and endpoints: - For $x=-2$: $$g(x)=e^{-(-2)^2}=e^{-4}$$ - For $x=0$: $$g(x)=e^{-0^2}=e^0=1$$ - For $x=1$: $$g(x)=e^{-(1^2)}=e^{-1}$$ From the values of $g(x)$ above, we conclude that $g(x)$ has the absolute maximum value of $1$ at $x=0$ and the absolute minimum value of $e^{-4}$ at $x=-2$.
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.