### Home > INT3 > Chapter 9 > Lesson 9.1.7 > Problem 9-89

9-89.

Evaluate each of the following trig expressions without using a calculator.

Every point on the unit circle is defined as

.

Where ison the unit circle?

Where is thevalue at that point?

See part (a).

When an angle is negative, it opens clockwise from

on the unit circle.

Find an equivalent angle between

by subtracting . Notice that the reference triangle is a triangle. Find the .

What is the

value in this location?

Remember the tangent is the ratio of

. undefined