NCHMCT JEE 2011 Question Paper with solutions for online practice

Since sin (A + B) = 1
⇒ sin (A + B) = sin 90°
∴ A + B = 90° ...(i)
Also, cos (A – B) = 1
⇒ cos (A – B) = cos 0°
∴ A – B = 0 ...(ii)
Adding eqn. (i) and (ii)
A = 45°, B = 45°