### Home > PC > Chapter 6 > Lesson 6.2.3 > Problem 6-95

6-95.

Suppose

*α*is an angle in Quadrant I and*β*is an angle in Quadrant IV such that sin*α*=and cos *β*=. Homework Help ✎ Find the exact value of cos

*α*.Find the exact value of sin

*β*.Find the exact value of sin(

*α*+*β*).Find the exact value of cos(

*α*+*β*).Use your calculator to approximate your answer to part (d).

Draw diagrams. Find the 3rd side for each triangle.

Draw diagrams. Find the 3rd side for each triangle.

Use the angle sum and difference formula for the sine.

Use the angle sum and difference formula for the cosine.