Question

The value of cos 5π/12  sin π/12 will be:

(A) 1/2√2

(B) 0

(C) - 1/2√2

(D) 1/√2

Answer 1

Answer is (D)

cos π/12 – sin π/12 = cos 15°- sin 15°

= cos (45° – 30°) – sin (45° – 30°)

= (cos 45° cos 30° + sin 45° sin 30°)

= (sin 45° cos 30° – cos 45° sin 30°)