Question

How do i establish this identity?

Answer 1

RHS

`\\ \sf\longmapsto (2 \tan( \theta) )/( \sin(2 \theta) ) \\ \\ \sf\longmapsto ( (2 \sin( \theta) )/(2 \cos( \theta) ) )/( \sin(2 \theta) ) \\ \\ \sf\longmapsto \frac{1}{ \cos {}^(2) ( \theta) } \\ \\ \sf\longmapsto {sec}^(2) \theta`