જો $A = 580^o$ હોય તો નીચેનામાંથી ક્યું સાચું છે ?
$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} $
$\frac{{\sin 3\theta - \cos 3\theta }}{{\sin \theta + \cos \theta }} + 1 = $
જો $\frac{{\cos x}}{a} = \frac{{\cos (x + \theta )}}{b} = \frac{{\cos (x + 2\theta )}}{c} = \frac{{\cos (x + 3\theta )}}{d} \, ,$ હોય તો $\left( {\frac{{a + c}}{{b + d}}} \right)$ =
$cot 5^o$ -$tan5^o$ -$2$ $tan10^o$ -$4$ $tan 20^o$ -$8$ $cot40^o$ =
$\cos \,\frac{\pi }{7}\,\cos \,\frac{{2\pi }}{7}\,\cos \,\frac{{3\pi }}{7}$ =
સાબિત કરો કે : $\cos 6 x=32 x \cos ^{6} x-48 \cos ^{4} x+18 \cos ^{2} x-1$