Question

Prove :.........3D%20%20%5Cfrac%7Bsinx%7D%7B1%20-%20cosx%7D%20" id="TexFormula1" title=" \sqrt{ \frac{1 + cosx}{1 - cosx} } = \frac{sinx}{1 - cosx} " alt=" \sqrt{ \frac{1 + cosx}{1 - cosx} } = \frac{sinx}{1 - cosx} " align="absmiddle" class="latex-formula">
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Answer 1

This is generally not true. Let x = 3π/2. Then

cos(3π/2) = 0

sin(3π/2) = -1

and

√((1 + cos(x)) / (1 - cos(x))) = √(1 / 1) = 1

while

sin(x) / (1 - cos(x)) = -1 / 1 = -1