Question

EMERALD PACKAGE 2
1.
Among the following, a rational number is
a) sin 15°
b) cos 15°
c) sin 15° cos 15°
d) sin 15° cos 75​

Answer 1

Answer:

Option (C).

Sin 15 cos 15 can be written as

= 1/2 2 sin 15 cos 15  (2 sin a cos a = sin 2a)

= 1/2 sin (2 * 15)

= 1/2 sin 30

= 1/2 * 1/2

= 1/4.