Question

If A=60° and B=30° show that, cos (A-B) = cos A cos B + sin A sin B​

Answer 1

Answer:

See the attachment. It can help you.

Step-by-step explanation:

LHS=RHS

Answer 2

Answer:

Given: A=60° and B =30° Now, LHS = Cos (A+B) ⇒ Cos (60° + 30°) ⇒ Cos (90°) ⇒ 0 [∵ cos 90° = 0] Now, RHS = Cos A Cos B – Sin A Sin B ⇒ cos(60°) cos(30°) – sin(60°) sin (30°) ⇒ 0 ∴ LHS = RHS Hence Proved