$\cot x - \tan x = $
$\cot \,2x$
$2{\cot ^2}x$
$2\,\,\cot \,2x$
${\cot ^2}\,2x$
The value of ${\sin ^2}{5^o} + {\sin ^2}{10^o} + {\sin ^2}{15^o} + ... + $ ${\sin ^2}{85^o} + {\sin ^2}{90^o}$ is equal to
Find the degree measures corresponding to the following radian measures (Use $\pi=\frac{22}{7}$ ).
$-4$
If $\tan \theta + \sin \theta = m$ and $\tan \theta - \sin \theta = n,$ then
Find the values of other five trigonometric functions if $\cot x=\frac{3}{4}, x$ lies in third quadrant.
If $\sin \theta + \cos \theta = m$ and $\sec \theta + {\rm{cosec}}\theta = n$, then $n(m + 1)(m - 1) = $