If $A = 580^o$ then which one of the following is true
$2\,\sin \left( {\frac{A}{2}} \right)\,\, = \,\,\sqrt {1 + \sin A} \, - \,\sqrt {1 - \sin A} $
$2\sin \left( {\frac{A}{2}} \right)\, = \,\, - \,\,\sqrt {1 + \sin A} \,\, + \,\sqrt {1 - \sin A} $
$2\sin \left( {\frac{A}{2}} \right)\, = \,\, - \,\,\sqrt {1 + \sin A} \,\, - \,\sqrt {1 - \sin A} $
$2\sin \left( {\frac{A}{2}} \right)\, = \,\,\,\,\sqrt {1 + \sin A} \,\, + \,\sqrt {1 - \sin A} $
$\sqrt 2 + \sqrt 3 + \sqrt 4 + \sqrt 6 $ is equal to
If $\frac{{2\sin \alpha }}{{\{ 1 + \cos \alpha + \sin \alpha \} }} = y,$ then $\frac{{\{ 1 - \cos \alpha + \sin \alpha \} }}{{1 + \sin \alpha }} = $
$\left( {1 + \cos \frac{\pi }{8}} \right)\,\left( {1 + \cos \frac{{3\pi }}{8}} \right)\,\left( {1 + \cos \frac{{5\pi }}{8}} \right)\,\left( {1 + \cos \frac{{7\pi }}{8}} \right) = $
$4 \,\,sin5^o \,\,sin55^o \,\,sin65^o$ has the values equal to
If $A + B + C = {180^o},$ then the value of $(\cot B + \cot C)$ $(\cot C + \cot A)\,\,(\cot A + \cot B)$ will be