$\frac{{\cos A}}{{1 - \sin A}} = $
$\sec A - \tan A$
${\rm{cosec}}\,A + \cot A$
$\tan \left( {\frac{\pi }{4} - \frac{A}{2}} \right)$
$\tan \left( {\frac{\pi }{4} + \frac{A}{2}} \right)$
$\cos \left(\frac{2 \pi}{7}\right)+\cos \left(\frac{4 \pi}{7}\right)+\cos \left(\frac{6 \pi}{7}\right)$ का मान बराबर होगा।
$3\,\left[ {{{\sin }^4}\,\left( {\frac{{3\pi }}{2} - \alpha } \right) + {{\sin }^4}\,(3\pi + \alpha )} \right]$ $ - 2\,\left[ {{{\sin }^6}\,\left( {\frac{\pi }{2} + \alpha } \right) + {{\sin }^6}(5\pi - \alpha )} \right] = $
$2\sin A{\cos ^3}A - 2{\sin ^3}A\cos A = $
यदि $\tan \alpha = \frac{1}{7}$ तथा $\sin \beta = \frac{1}{{\sqrt {10} }}\left( {0 < \alpha ,\,\beta < \frac{\pi }{2}} \right)$, तब $2\beta $ बराबर है
निम्नलिखित को सिद्ध कीजिए
$\frac{\sin 5 x+\sin 3 x}{\cos 5 x+\cos 3 x}=\tan 4 x$