### Home > A2C > Chapter 13 > Lesson 13.2.3 > Problem13-130

13-130.
1. Write each angle as the sum or difference of two special angles and then find the exact sine or cosine. Homework Help ✎

$\text{What two special angles have a sum of }\frac{7\pi}{12}?\,\,\,\,\text{sin}\left(\frac{\pi}{3}+\frac{\pi}{4}\right)$

Now find the exact value of sine.

$\text{sin}\left(\frac{\pi}{3}+\frac{\pi}{4}\right)=\frac{\sqrt{6}+\sqrt{2}}{4}$

See part (a).

$\text{Use }\left(\frac{7\pi}{6}-\frac{\pi}{4}\right)$