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Question
Prove the following:
`(cos(pi + x) cos(-x))/(sin(pi - x)cos(pi/2 + x))` = cot2x
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Solution
L.H.S. = `(cos(pi + x) cos(-x))/(sin(pi - x)cos(pi/2 + x))`
= `((-cosx)(cosx))/((sinx)(-sinx)`
= `cos^2x/sin^2x`
= cot2x
= R.H.S.
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