જો $x = \sin {130^o}\,\cos {80^o},\,\,y = \sin \,{80^o}\,\cos \,{130^o},\,\,z = 1 + xy,$ તો આપેલ પૈકી ક્યૂ સત્ય છે.
$x > 0,\,\,y > 0,\,\,z > 0$
$x > 0,\,\,y < 0,\,\,0 < z < 1$
$x > 0,\,\,y < 0,\,\,z > 1$
$x < 0,\,\,y < 0,\,0 < z < 1$
$\sqrt {2 + \sqrt {2 + 2\cos 4\theta } } = $
$\frac{{\tan \,\left( {{\textstyle{{3\,\pi } \over 2}}\,\, - \,\,\alpha } \right)\,\,\,\cos \,\left( {{\textstyle{{3\,\pi } \over 2}}\,\, - \,\,\alpha } \right)}}{{\cos \,(2\,\pi \,\, - \,\alpha )}}$ $+ cos \left( {\alpha \,\, - \,\,\frac{\pi }{2}} \right) \,sin (\pi -\alpha ) + cos (\pi +\alpha ) sin \,\left( {\alpha \,\, - \,\,\frac{\pi }{2}} \right)$ =
જો $\tan \frac{\theta }{2} = t,$ તો $\frac{{1 - {t^2}}}{{1 + {t^2}}} = . . . .$
$1 + \cos 2x + \cos 4x + \cos 6x = $
જો $\frac{x}{{\cos \theta }} = \frac{y}{{\cos \left( {\theta - \frac{{2\pi }}{3}} \right)}} = \frac{z}{{\cos \left( {\theta + \frac{{2\pi }}{3}} \right)}},$ તો $x + y + z = $