Given:

To find: Values of sin4x

We know,

sin² x + cos² x = 1

⇒ cos² x = 1 – sin² x

Since,

⇒cosx will be negative in first quadrant

So,

We know,

sin 2x = 2 sin x cos x

cos 2x = 2 cos² x – 1

Therefore,

sin 4x = 2 sin 2x cos 2x

⇒ sin 4x = 2 (2 sin x cos x) (2 cos² x – 1)

Hence, value of