Algebra and Trigonometry 10th Edition

Published by Cengage Learning
ISBN 10: 9781337271172
ISBN 13: 978-1-33727-117-2

Chapter 7 - 7.1 - Using Fundamental Identities - 7.1 Exercises - Page 513: 15



Work Step by Step

One of the Pythagorean Identities is: $1+tan^2x=sec^2x$ Also: $sec~x=\frac{1}{cos~x}~→~cos~x=\frac{1}{sec~x}$ $cos~x(1+tan^2x)=\frac{1}{sec~x}sec^2x=sec~x$
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.