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Help me please!!!

Help me understand why sin2x+cos3x. Equals = 2sinxcosx+4cos³x-3cosx

Use the double identity

User Mangusta
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1 Answer

3 votes

Explanation:

sin(2x) + cos(3x)

Use double angle formula sin(2x) = 2 sin x cos x.

Use triple angle formula cos(3x) = 4 cos³x − 3 cos x.

Substitute:

2 sin x cos x + 4 cos³x − 3 cos x

User Rocking
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