Precalculus (10th Edition)

Published by Pearson
ISBN 10: 0-32197-907-9
ISBN 13: 978-0-32197-907-0

Chapter 6 - Trigonometric Functions - Chapter Review - Chapter Test - Page 436: 21

Answer

$\sin\theta=\dfrac{12}{13}$ $\cos\theta=-\dfrac{5}{13}$ $\cot\theta=-\dfrac{5}{12}$ $\sec\theta=-\dfrac{13}{5}$ $\csc\theta=\dfrac{13}{12}$

Work Step by Step

Determine $\sec\theta$: $\tan^2\theta+1=\sec^2\theta$ $\left(-\dfrac{12}{5}\right)^2+1=\sec^2\theta$ $\sec\theta=\pm\sqrt{\dfrac{169}{25}}=\pm\dfrac{13}{5}$ Because the angle $\theta$ is in Quadrant II, we have: $\sec\theta=-\dfrac{13}{5}$ Determine $\cos\theta,\sin\theta,\cot\theta,\csc\theta$: $\cos\theta=\dfrac{1}{\sec\theta}=\dfrac{1}{-\frac{13}{5}}=-\dfrac{5}{13}$ $\sin\theta=\cos\theta\cdot\tan\theta=-\dfrac{5}{13}\cdot \left(-\dfrac{12}{5}\right)=\dfrac{12}{13}$ $\cot\theta=\dfrac{1}{\tan\theta}=\dfrac{1}{-\frac{12}{5}}=-\dfrac{5}{12}$ $\csc\theta=\dfrac{1}{\sin\theta}=\dfrac{1}{\frac{12}{13}}=\dfrac{13}{12}$
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.