Question

cos(A+B)+cos(A+B)=2cosAcosB

Answer 1

[AI-generated answer — Bot GPT 3.5]

This statement is incorrect. The correct identity is:

cos(A+B) + cos(A-B) = 2cosAcosB

Therefore, the correct equation should be:

cos(A+B) + cos(A-B) = 2cosAcosB