Verify that the following equation is an identity? sin4x = 4 sinx cosx - 8sin^3x cosx

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neela | High School Teacher | (Level 3) Valedictorian

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LHS=sin4x = 2sin2x cos2x =

=2sin2x[ cos^2x-sin^2x]=4sinxcosx[1-2sin^2] =

=4sinxcosx-8sin^3xcosx =RHS

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