91Ó°ÊÓ

In Exercises 1-14, find the exact values of the indicated trigonometric functions using the unit circle. $$ \cos \left(\frac{3 \pi}{4}\right) $$

In Exercises 1-12, find the exact length of each arc made by the indicated central angle and radius of each circle. $$ \theta=8^{\circ}, r=1500 \mathrm{~km} $$

In Exercises 1-14, find the exact values of the indicated trigonometric functions using the unit circle. $$ \csc \left(\frac{11 \pi}{6}\right) $$

In Exercises 11-20, find the distance traveled (arc length) of a point that moves with constant speed \(v\) along a circle in time \(t\). $$ v=120 \mathrm{ft} / \mathrm{sec}, t=27 \mathrm{~min} $$

In Exercises 15-30, use the unit circle and the fact that sine is an odd function and cosine is an even function to find the exact values of the indicated functions. $$ \cos \left(-\frac{3 \pi}{4}\right) $$

In Exercises 15-30, use the unit circle and the fact that sine is an odd function and cosine is an even function to find the exact values of the indicated functions. $$ \sin \left(-270^{\circ}\right) $$

In Exercises 25-36, use a calculator to approximate the length of each arc made by the indicated central angle and radius of each circle. Round answers to two significant digits. $$ \theta=\frac{\pi}{10}, r=6 \mathrm{ft} $$

In Exercises 15-30, use the unit circle and the fact that sine is an odd function and cosine is an even function to find the exact values of the indicated functions. $$ \cos \left(-90^{\circ}\right) $$

In Exercises 31-50, use the unit circle to find all of the exact values of \(\theta\) that make the equation true in the indicated interval. $$ \cos \theta=\frac{\sqrt{3}}{2}, 0 \leq \theta \leq 2 \pi $$

$$ \text { In Exercises } 25-38 \text {, convert each angle measure from radians to degrees. } $$ $$ 9 \pi $$