Thomas' Calculus 13th Edition

Published by Pearson
ISBN 10: 0-32187-896-5
ISBN 13: 978-0-32187-896-0

Chapter 11: Parametric Equations and Polar Coordinates - Practice Exercises - Page 688: 22

Answer

$2\pi(2-\dfrac{3\sqrt 2}{4})$

Work Step by Step

Here, $ \dfrac{dx}{dt}= 2t-(\dfrac{1}{2t^2}) ;y=4\sqrt t$ This implies that $ \dfrac{dy}{dt}= \dfrac{2}{\sqrt t}$ Surface area: $S=\int_{(1/\sqrt 2)}^{1} 2\pi [t^2+(\dfrac{1}{2t})] \sqrt { [(2t-\dfrac{1}{2t^2})^2 +(\dfrac{2}{\sqrt t})^2}] dt$ Then, $S=(2 \pi)[(\dfrac{1}{2)}t^4+(\dfrac{3}{2}) t-(\dfrac{1}{8})t^{-2}]_{(1/\sqrt 2)}^{1}$ Hence, $S=2\pi(2-\dfrac{3\sqrt 2}{4})$
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.