Question

HELP :Write the expression as the
sine or cosine of an angle.

Answer 1

sin(4π/21)

Explanation:

Step 1: Rearrange expression

sin(π/3)cos(π/7) - cos(π/3)sin(π/7)

Step 2: Use sin(A ± B)

sin(π/3 - π/7)

Step 3: Evaluate

sin(4π/21)

And we have our answer!