Question

How do you use the sum-to-product formulas to write the given expression as a product sin7θ-sin5θ?

Answer 1

See below.

Explanation:

Your query is only about actual useage, so here it is:

`sin 7 theta - sin 5 theta`

`= 2 cos ((7 theta + 5 theta)/2) sin ((7 theta - 5 theta)/2)`

`= 2 cos 6 theta sin theta`