SSC CGL 7 Sep 2016 Paper

$\mathit{s}\mathit{e}{\mathit{c}}^{2}17°$ - $\frac{1}{\mathit{t}\mathit{a}{\mathit{n}}^{2}73°}$ - sin 17° sec 73°
= $\mathit{s}\mathit{e}{\mathit{c}}^{2}17°-\mathit{c}\mathit{o}{\mathit{t}}^{2}73°$ - sin 17° . sec 73°
= $\mathit{s}\mathit{e}{\mathit{c}}^{2}17°-\mathit{c}\mathit{o}{\mathit{t}}^2\left(90-17\right)°$ - sin 17° . sec (90° - 17°)
= $\mathit{s}\mathit{e}{\mathit{c}}^2{17}^2$ - $\mathit{t}\mathit{a}{\mathit{n}}^2$ 17° - sin 17° . cosec 17°
= 1 - 1 = 0
[Since cot (90° – θ ) = tan θ ; sec (90° – θ ) = cosec θ ; $\mathit{s}\mathit{e}{\mathit{c}}^2$ θ – $\mathit{t}\mathit{a}{\mathit{n}}^2$ θ = 1; sinq . cosec θ = 1]