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Trig Identities

Prove

1 - sin2x / cosx = sin2x / 2sinx

I tried do both LHS and RHS. Got stuck after a step or two.

Comments

Hi Lawson, have you written out your question correctly? Is the equation supposed to be
1 - sin2x/cosx = sin2x/2sinx instead of what you have written?
 
 

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1 Answer

(1-sin2x)/cosx=sin2x/2sinx
cos2x/cosx=cosx
sin2x/2sinx=2sinxcosx/2sinx=cosx