Question

$\frac{ {x}^{ - 1} }{ {x^{ - 1} + y}^{-1}} + \frac{ {x}^{ - 1} }{x ^{ - 1} - y ^{ - 1} } = \frac{2 {y}^{2} }{ {y}^{2} - x^{2} }$
prove that : ​

Answer 1

*answer in the attachment