Question

verifysin3theta=3sintheta-4sinque theta by taking theta=30°​

Answer 1

Given:

• θ = 30°

To Prove:

sin 3θ = 3 sinθ - 4 sin³θ

Solution:

First let's consider the LHS:

sin 3θ = sin 3(30) = sin 90° = 1

Now consider the RHS:

3 sinθ - 4 sin³θ

= 3 (sin 30°) - 4 (sin 30°)³

= [3 × ½] - [4 (½)³]

= 3/2 - 1/2

= 2/2

= 1

LHS = RHS

★ HENCE PROVED ★

Know more:

• sin²θ + cos²θ = 1
• 1 + cot²θ = cosec²θ
• 1 + tan²θ = sec²θ