### Home > INT3 > Chapter 12 > Lesson 12.2.3 > Problem12-108

12-108.

Write as the difference of two special angles. Then use the appropriate angle difference formula to calculate the exact sine and cosine of . Homework Help ✎

you can use the Angle Difference Identity.
Refer to the Math Notes in Lesson 12.2.3.

Substitute the angles into the Angle Difference Identity.

$\text{sin }\left (\frac{\pi}{3}-\frac{\pi}{4} \right )=\text{ sin }\left (\frac{\pi}{3} \right ) \cdot \text{cos } \left (\frac{\pi}{4} \right ) - \text{cos} \left (\frac{\pi}{3} \right) \cdot \text{sin } \left (\frac{\pi}{4} \right )$

Substitute the exact values for each part of the equation.
Then simplify the multiplication and subtraction.

Repeat this process for cosine.