1.

Prove that (i) cos(π4+x)+ cos(π4−x) = √2 cos x (ii) cos(3π4+x)− cos(3π4−x) =− √2 sin x

Answer»

Prove that

(i) cos(π4+x)+ cos(π4x) = 2 cos x

(ii) cos(3π4+x) cos(3π4x) = 2 sin x



Discussion

No Comment Found