${(\cos \alpha + \cos \beta )^2} + {(\sin \alpha + \sin \beta )^2} = $
$4{\cos ^2}\frac{{\alpha - \beta }}{2}$
$4{\sin ^2}\frac{{\alpha - \beta }}{2}$
$4{\cos ^2}\frac{{\alpha + \beta }}{2}$
$4{\sin ^2}\frac{{\alpha + \beta }}{2}$
$\sqrt {2 + \sqrt {2 + 2\cos 4\theta } } = $
સાબિત કરો કે, $=\frac{\sin 5 x-2 \sin 3 x+\sin x}{\cos 5 x-\cos x}=\tan x$
$\sin {163^o}\cos {347^o} + \sin {73^o}\sin {167^o} = $
$\sin 600^\circ \cos 330^\circ + \cos 120^\circ \sin 150^\circ =....$
જો $a\,\cos 2\theta + b\,\sin 2\theta = c$ ના બીજ $\alpha$ અને $\beta$ હોય તો $\tan \alpha + \tan \beta = . . .$