( * )If sin theta + cos theta = a and tan theta + cot theta = b then b (a square –1) =

Hi,

Folow the following steps :

Put the values of a & b in the expression and expand the second bracket , u will see that the remaining term in second bracket is 2SINxCOSx. Now multiply this term with the first bracket and take the terms out which are common . You will see that the final answer is reducing to 2 after you applied SIN^2+COS^2=1 identity.