Math - Trigonometry Identity proof?

Question

Can you please verify the following identity: (4sinxcosx)(1-2(sin^2)(x))=sin4x.

Answer 1

Step 1:

The trigonometric identity is .

Consider left hand side identity .

Rewrite the identity .

Double Angle Formula for trigonometric identitites: .

Substitute in the trigonometric identity.

Fundamental identities: .

Double Angle Formula for trigonometric identitites: .

Double Angle Formula for trigonometric identitites: .

= Right hand side identity.

Hence, Left hand side identity is equal to Right hand side identity.

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Solution :

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