જો $x + \frac{1}{x} = 2\,\cos \theta ,$ તો ${x^3} + \frac{1}{{{x^3}}} = $

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

જો $tan\ 80^o = a$ અને $tan47^o = b$ હોય તો $tan37^o$ =

સમીકરણ $\frac{{{{\tan }^2}20^\circ  - {{\sin }^2}20^\circ }}{{{{\tan }^2}20^\circ \,\cdot\,{{\sin }^2}20^\circ }}$ = 

$\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) = $

${\cos ^2}\,{10^o}\,\, - \,\cos \,\,{10^o}\,\cos \,\,{50^o}\, + \,{\cos ^2}\,{50^o}$ ની કિમત ..... થાય.