Trigonometry (10th Edition)

Published by Pearson
ISBN 10: 0321671775
ISBN 13: 978-0-32167-177-6

Chapter 2 - Review Exercises - Page 88: 6

Answer

$\theta = 30^{\circ}$

Work Step by Step

Use the concept of cofunctions $\sin x = \cos (90^{\circ} - x)$ $\cos (\frac{3\theta}{5} + 11^{\circ}) = \sin (\frac{7\theta}{10}+40^{\circ})$ $\cos (\frac{3\theta}{5} + 11^{\circ}) = \cos (90^{\circ} -\frac{7\theta}{10} -40^{\circ})$ $\frac{3\theta}{5} + 11^{\circ} = 90^{\circ} -\frac{7\theta}{10} -40^{\circ} $ $\frac{13\theta}{10} = 39^{\circ}$ $\theta = 30^{\circ}$
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.