Calculus: Early Transcendentals (2nd Edition)

Published by Pearson
ISBN 10: 0321947347
ISBN 13: 978-0-32194-734-5

Chapter 14 - Vector Calculus - Review Exercises - Page 1148: 8

Answer

$125 \pi$

Work Step by Step

In order to compute the integral we will use the following formula: $\oint F \ dr=\int_m^{n} F[r(t)] r'(t) \ dt$ Here, the curve is given as: $r(t)= (5 \cos t, 5 \sin t)$ This implies that $r'(t) = (-5 \sin t, 5 \cos t) \implies |r'(t)|=\sqrt {(-5 \sin t)^2+(5 \cos t)^2}=5$ Therefore, the integral is: $\oint F \ dr=\int_0^{\pi} F[r(t)] r'(t) \ dt\\=\int_0^{\pi} (25 \sin^2 t-(2) (5\sin t)(5 \cos t)+25 \cos^2 t) \cdot 5 \ dt\\=5 \times \int_0^{ \pi} (25-50 \sin t \cos t) \ dt \\=5 \times [25(t)+25 \cos^2 t]_0^{\pi}\\=125 \pi $
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.