### Home > INT3 > Chapter 12 > Lesson 12.2.3 > Problem 12-109

12-109.

Write each angle as the sum or difference of two special angles and then calculate the exact sine or cosine.

Refer to problem 12-108. Find a way to add or subtract two familiar angles from the unit circle to get the desired angle.

Then use the appropriate identity from the Math Notes in Lesson 12.2.3.

Use the same method as part (a).