Calculus 8th Edition

Published by Cengage
ISBN 10: 1285740629
ISBN 13: 978-1-28574-062-1

Chapter 16 - Vector Calculus - 16.2 Line Integrals - 16.2 Exercises - Page 1126: 36

Answer

$(x, y, z) = (\frac{3\pi (2 \pi^2 + 1)}{4\pi^2 + 3}, 0, 0)$

Work Step by Step

$x = t$ $y = \cos(t)$ $z = \sin(t)$ $0 \leq t \leq 2\pi$ $m = \int_c(x^2 + y^2 + z^2) ds$ $= \int_c^{2\pi}f(t)\sqrt {(f_x(x, y, z)^2 + f_y(x, y, z)^2 + f_z(x, y, z)^2)}dt$ $ = \int_0^{2\pi} (t^2 + 1) \sqrt {(1)^2 + (-\sin t(t))^2 + (\cos(t)^2)} dt$ $ = \int_0^{2\pi}(t^2 + 1)\sqrt {2}dt$ $ = \sqrt {2}(\frac{8}{3}\pi^3 + 2\pi)$ $x = \frac{1}{m}\int_c xp(x, y, z)ds$ $ = \frac{1}{\sqrt {2}(\frac{8}{3}\pi^3 + 2\pi)}\int_0^{2\pi} t(t^2 + 1)\sqrt {2}dt$ $ = \frac{1}{\sqrt {2}(\frac{8}{3}\pi^3 + 2\pi)}\int_0^{2\pi}\sqrt {2} (t^3 + t^2)dt$ $ = \frac{4\pi^4 + 2\pi^2}{\frac{8}{3}\pi^3 + 2\pi}$ $ = \frac{3\pi(2\pi^2 + 1)}{4\pi^2 + 3}$ $y = \frac{1}{m}\int_c yp(x, y, z)ds$ $ = \frac{3}{2\sqrt {2}\pi(4\pi^2 + 3)}\int_0^{2\pi}(\sqrt {2}\cos(t))(t^2 + 1)dt$ $ = 0$ $z = \frac{1}{m}\int_c zp(x, y, z)ds$ $ = \frac{3}{2\sqrt {2}\pi(4\pi^2 + 3)}\int_0^{2\pi}(\sqrt {2}\sin(t))(t^2 + 1)dt$ $ = 0$ Therefore: $(x, y, z) = (\frac{3\pi (2 \pi^2 + 1)}{4\pi^2 + 3}, 0, 0)$
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.