यदि $(\sec A + \tan A)\,(\sec B + \tan B)\,(\sec C + \tan C)$$ = \,(\sec A - \tan A)\,(\sec B - \tan B)\,(\sec C - \tan C),$ तब प्रत्येक पक्ष बराबर है

$\sqrt 3 \,{\rm{cosec}}\,{20^o} - \sec \,{20^o} = $

$\cos \frac{\pi }{5}\cos \frac{{2\pi }}{5}\cos \frac{{4\pi }}{5}\cos \frac{{8\pi }}{5} = $

यदि $\sin A = n\sin B,$ तो $\frac{{n - 1}}{{n + 1}}\tan \,\frac{{A + B}}{2} = $

${(\cos \alpha + \cos \beta )^2} + {(\sin \alpha + \sin \beta )^2} = $

यदि $cos A = {3\over 4} , $ तब $32\sin \left( {\frac{A}{2}} \right)\sin \left( {\frac{{5A}}{2}} \right) = $