$\displaystyle cosecA+cosec2A+cosec4A=cot\frac{A}{4}-cot4A$
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Originally Posted by srirahulan $\displaystyle cosecA+cosec2A+cosec4A=cot\frac{A}{4}-cot4A$ This is not true in general. Try, for example, $\displaystyle A=\frac\pi3$.
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