Question

if tanA =1,tanB= root3 evaluate cos A cos B - sin A sin B​

Answer 1

A=45

B=60

now,

cos A cos B - sin A sin B

=cos 45 cos 60 - sin 45 sin60

=1/root2×1/2 -1/root2×root3/2

=1/root2 (1/2×root3/2)

=root3/4×root2