Question

if tan a =1/3 and tan b=1/2 then cos 2a-sin 2b

Answer 1

Answer:

Given: tan(A+B) = 1/2 and tan(A-B) = 1/3, Now let A+B = X and A-B = Y i.e ... tan(2A) = tan(X+Y) = [tan(X) + tan(Y)]/[1 - tan(X).tan(Y)], = (1/2 + 1/3)/[1 - (1/