Trigonometry (10th Edition)

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

Chapter 2 - Review Exercises - Page 89: 12

Answer

In letter D, the angle $140^{\circ}$ has no reference angle that is a special angle.

Work Step by Step

All the trigonometric functions in A, B, and C can be solved using reference angles that are special. ($30^{\circ}, 45^{\circ}, 60^{\circ}, 90^{\circ}$) But, in letter D, the angle $140^{\circ}$ has no reference angle that is a special angle.
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.