Add full rotations of until the angle is between and .

Apply the reference angle by finding the angle with equivalent trig values in the first quadrant.

The exact value of is .

Add full rotations of until the angle is between and .

Apply the reference angle by finding the angle with equivalent trig values in the first quadrant. Make the expression negative because sine is negative in the fourth quadrant.

The exact value of is .

Set up the coordinates .

Find the Value Using the Unit Circle -pi/4