જો $a{\sin ^2}x + b{\cos ^2}x = c,\,\,$$b\,{\sin ^2}y + a\,{\cos ^2}y = d$ અને $a\,\tan x = b\,\tan y,$ તો $\frac{{{a^2}}}{{{b^2}}} = . . ..$
$\frac{{(b - c)\,\,(d - b)}}{{(a - d)\,\,(c - a)}}$
$\frac{{(a - d)\,\,(c - a)}}{{(b - c)\,\,(d - b)}}$
$\frac{{(d - a)\,\,(c - a)}}{{(b - c)\,\,(d - b)}}$
$\frac{{(b - c)\,\,(b - d)}}{{(a - c)\,\,(a - d)}}$
$4 \,\,sin5^o \,\,sin55^o \,\,sin65^o$ =
$\frac{{\sin {{81}^o} + \cos {{81}^o}}}{{\sin {{81}^o} - \cos {{81}^o}}}$=
જો $A + B + C = \pi ,$ તો $\frac{{\cos A}}{{\sin B\sin C}} + \frac{{\cos B}}{{\sin C\sin A}} + \frac{{\cos C}}{{\sin A\sin B}} = $
જો $\cos 3\theta = \alpha \cos \theta + \beta {\cos ^3}\theta ,$ તો $(\alpha ,\beta ) = $
જો $\tan \theta = \frac{{\sin \alpha - \cos \alpha }}{{\sin \alpha + \cos \alpha }},$ તો $\sin \alpha + \cos \alpha $ અને $\sin \alpha - \cos \alpha $ ની કિમત . . . . ને સમાન થવી જ જોઈએ.