### Home > PC > Chapter 6 > Lesson 6.2.1 > Problem 6-74

6-74.

Christina stared at the equation *“That’s interesting,”* she thought. *“Since **, this must mean that and . But that’s impossible.”*.

Why is it impossible?

What is the range of sine and cosine?

What is going on here?

Solve for

if*.*Using a calculator, evaluate

. There is another solution. Use the unit circle to help you calculate the second solution.