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Prove that (Cosx-Cos³x)/Sinx=SinxCosx​

User AlterX
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Answer:

(Cosx-Cos³x)/Sinx=SinxCosx

Explanation:

sin3x−cos3x

=sinxsin2x−cosxcos2x

=sinx(1−cos2x)−cosx(1−sin2x)

=sinx−sinxcos2x−cosx+cosxsin2x

=sinx−cosx+(sinx−cosx)sinxcosx

=(sinx−cosx)(1+sinxcosx

User Djolf
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