141k views
17 votes
Rewrite the product as a sum or difference.
sin(-x) sin(9x)

User Caampa
by
8.7k points

1 Answer

9 votes

Answer:

[cos(10x) - cos(8x)]/2

Explanation:

sin(-x) sin(9x) = {cos[9x - (-x)] - cos(9x + (-x)]}/2

= [cos(10x) - cos(8x)]/2

User Egghead
by
7.3k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories