Prove the following : cos60°.cos30° – sin60°. sin30° = cos 90°

Question

Philoid · Accepted Answer

We know that

cos(90^o) = 0

Taking LHS

= 0

Now, RHS = cos 90° = 0

∴ LHS =RHS

Hence, proved.

Prove the following :cos60°.cos30° – sin60°. sin30° = cos 90°