$\tan 1^\circ \tan 2^\circ \tan 3^\circ \tan 4^\circ ……..\tan 89^\circ = $

 $1 – \frac{{{{\sin }^2}y}}{{1 + \cos \,y}} + \frac{{1 + \cos \,y}}{{\sin \,y}} – \frac{{\sin \,\,y}}{{1 – \cos \,y}}  =$

જો  $x = \sec \theta + \tan \theta ,$ તો  $x + \frac{1}{x} = $

$(m + 2)\sin \theta + (2m – 1)\cos \theta = 2m + 1,$ જો . . . 

જો  $\sin \theta + \cos \theta = m$ અને $\sec \theta + {\rm{cosec}}\theta = n$, તો  $n(m + 1)(m – 1) = $