The value of the expression $1 - \frac{{{{\sin }^2}y}}{{1 + \cos \,y}} + \frac{{1 + \cos \,y}}{{\sin \,y}} - \frac{{\sin \,\,y}}{{1 - \cos \,y}}$ is equal to
$0$
$1$
$\sin \,y$
$\cos \,y$
Find the value of:
$\sin 75^{\circ}$
If $\sin \theta + \cos \theta = 1$, then $\sin \theta \cos \theta = $
If $\tan \theta + \sin \theta = m$ and $\tan \theta - \sin \theta = n,$ then
If $\sin x + {\rm{cosec}}\,x = 2,$ then $sin^n x + cosec^n x$ is equal to
If $x + \frac{1}{x} = 2\cos \alpha $, then ${x^n} + \frac{1}{{{x^n}}} = $