$2{\cos ^2}\theta - 2{\sin ^2}\theta = 1$, तो $\theta  =$ ..........$^o$ 

यदि $\cos A = \frac{3}{4}$, तब  $32\sin \frac{A}{2}\cos \frac{5}{2}A = $

यदि $A + B + C = {180^o},$ तब  $\frac{{\sin 2A + \sin 2B + \sin 2C}}{{\cos A + \cos B + \cos C - 1}} = $

यदि $\cos 3\theta = \alpha \cos \theta + \beta {\cos ^3}\theta ,$ तो $(\alpha ,\beta ) = $

${\sin ^2}\frac{\pi }{8} + {\sin ^2}\frac{{3\pi }}{8} + {\sin ^2}\frac{{5\pi }}{8} + {\sin ^2}\frac{{7\pi }}{8} = $

$\sin 600^\circ \cos 330^\circ  + \cos 120^\circ \sin 150^\circ $ का मान होगा