Question

2 sin A cos³ A – 2 sin³ A cos A = ______.

विकल्प

• sin 4A

• `1/2 sin 4A`

• `1/4 sin 4A`

• None of these

Answer 1

2 sin A cos³ A – 2 sin³ A cos A = `underlinebb(1/2 sin  4A)`.

Explanation:

2 sin A cos³ A – 2 sin³ A cos A

= 2 sin A cos A(cos² A – sin² A)

= 2 sin A cos A cos 2A

= sin 2A cos 2A

= `1/2` sin 4A