If $A + B + C = {180^o},$ then the value of $\cot \frac{A}{2} + \cot \frac{B}{2} + \cot \frac{C}{2}$ will be
$2\cot \frac{A}{2}\cot \frac{B}{2}\cot \frac{C}{2}$
$4\cot \frac{A}{2}\cot \frac{B}{2}\cot \frac{C}{2}$
$\cot \frac{A}{2}\cot \frac{B}{2}\cot \frac{C}{2}$
$8\,\cot \frac{A}{2}\cot \frac{B}{2}\cot \frac{C}{2}$
If $x = \sin {130^o}\,\cos {80^o},\,\,y = \sin \,{80^o}\,\cos \,{130^o},\,\,z = 1 + xy,$which one of the following is true
If $A + B + C = \pi \,(A,B,C > 0)$ and the angle $C$ is obtuse then
If $\tan \,(A + B) = p,\,\,\tan \,(A - B) = q,$ then the value of $\tan \,2A$ in terms of $p$ and $q$ is
Prove that $=\frac{\sin 5 x-2 \sin 3 x+\sin x}{\cos 5 x-\cos x}=\tan x$
If $2\sec 2\alpha = \tan \beta + \cot \beta ,$ then one of the values of $\alpha + \beta $ is