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Trig Proof

paulo1913
in Homework Help

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How do I prove that:

 

(cosx-cos3x)/(sin3x-sinx)= tan2x?

How do I prove that:

 

(cosx-cos3x)/(sin3x-sinx)= tan2x?

 

 

do you want the proof?

use the following identites

 

sin2x = 2sinxcosx

cos2x = 1-2sin^2x

 

cos3x = 4cos^3x - 3cosx

sin3x = 3sinx -4sin^3x - sinx

 

i did the proof its actually pretty simple.. good luck

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