I got this expression while solving a problem.
we need to find the range of y
The Attempt at a Solution
Numerator of RHS lies between sin2a-1 and 1+sin2a
Denominator lies between -1-sin2a and 1-sin2a
so RHS lies between (sin2a-1)/(-1-sin2a) and (1+sin2a)/(1-sin2a)
on solving I got y lies between tan^2 (45-a) and tan^2 (45+a)
but the answer is opposite (i.e. y does not lie between them).