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Rewrite with only sin x and cos x.
sin 3x - cos x

User Uliwitness
by
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1 Answer

3 votes

Answer:

sin 3x - cos x = 3 (sin x)(cos x)(cos x) -(sin x)(sin x)(sin x) -cos x

Explanation:

sin 3x - cos x

This uses Trig Identities.

sin 3x = sin (x + x + x) = sin (x+x)*cos x + cos (x + x) sin x

= 2sinxcosx * cos x + [ (cos x)(cos x) -(sin x)(sin x) ] (sin x)

sin 3x - cos x = 2sinxcosx * cos x + [ (cos x)(cos x) -(sin x)(sin x) ] (sin x) -cos x

sin 3x - cos x = 2sinxcosx * cos x + sinx (cos x)(cos x) -(sin x)(sin x)(sin x) -cos x

sin 3x - cos x = 3 sinx cosx * cos x -(sin x)(sin x)(sin x) -cos x

sin 3x - cos x = 3 (sin x)(cos x)(cos x) -(sin x)(sin x)(sin x) -cos x

User MoominTroll
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7.0k points