Trigonometry (10th Edition)

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

Chapter 1 - Trigonometric Functions - Section 1.4 Using the Definitions of the Trigonometric Functions - 1.4 Exercises: 85

Answer

negative

Work Step by Step

If initial angle $90^{\circ}\leq\theta\leq 180^{\circ}$, then the double angle will be $180^{\circ}\leq2\theta\leq 360^{\circ}$. In this range the y is negative therefore the sine will be negative (remember that r is always positive)
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.