### Home > A2C > Chapter 9 > Lesson 9.3.2 > Problem 9-155

9-155.

For each equation, find two solutions 0 <

*x*< 2, which make the equation true. No calculator necessary. Homework Help ✎tan

*x*=sin

*x*= 0cos

*x*=

What angle has the cosine of negative one half? Think of 30°, 60° right triangles.

*x* = 120° or 240°

Now convert the angles into radians.

See part (a).

If sin(*x*) = 0, y = 0

*x* = 0

Remember the side ratios of 45° right triangles.