Trigonometry 7th Edition

Published by Cengage Learning
ISBN 10: 1111826854
ISBN 13: 978-1-11182-685-7

Chapter 1 - Section 1.3 - Definition I: Trigonometric Functions - 1.3 Problem Set - Page 32: 38


$\cos{\theta} = \dfrac{x}{r}$. Since $r \ge x$, then the value of $\dfrac{x}{r}$, which is also the value of $\cos{\theta}$, will always be less than or equal to $1$.

Work Step by Step

Definition I states that $\cos{\theta}= \dfrac{x}{r}$. Figure 1 shows that $r$ is the hypotenuse (longest side) of the right triangle, while $x$ and $y$ are the legs. Since $r\ge x$, then $\frac{x}{r}$ will be less than or equal to $1$ Thus,for any angle in standard position, $\cos{\theta} \le 1$.
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.