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Question
Prove the following:
`cos ((3pi)/ 2 + x ) cos(2pi + x) [cot ((3pi)/2 - x) + cot (2pi + x)]= 1`
Solution
`cos ((3pi)/ 2 + x ) cos(2pi + x) [cot ((3pi)/2 - x) + cot (2pi + x)]`
= sin x cos x `[cot((3x)/2-x) + cot (2pi + x)]`
= sin x cos x [tanx + cot x]
= sin x cos x `[(sinx + cos x)/(cos x + sin x)]`
= sin x cos x `(1/(sinx cosx))=1`
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