### Home > A2C > Chapter 10 > Lesson 10.1.1 > Problem 10-15

10-15.

Solve each equation for *one* answer. Most of these problems have more than one answer. Think about all four quadrants.

Remember the angles from special right triangles.

Simplify the equation first.

This is not one of the special angles.

Use a calculator to find one answer.

Looking at a unit circle may help you find the other answer.