Question

1/ 1+cosA + 1/ 1-cosA = 2 cosec square A​

Answer 1

$\frac{1}{1 + \csc( \alpha ) } + \frac{1}{1 - \csc( \alpha ) }$

$= \frac{1 + \csc( \alpha ) +1 - \csc( \alpha ) }{1 ^{2} - \csc( \alpha ) ^{2} }$

$= \frac{2}{sec ^{2} \alpha }$

$= 2 \csc ^{2} ( \alpha )$