$\sec{2} x = \frac{1}{a}$  হলে,

a=sinx হলে, x এর মান কত?[0

$\sec 2 \mathrm{x}=\frac{1}{\mathrm{a}}=\frac{1}{\sin \mathrm{x}}$

$\begin{array}{l} \Rightarrow \cos 2 x=\sin x \\ \Rightarrow 1-2 \sin ^{2} x=\sin x \\ \Rightarrow 2 \sin ^{2} x+\sin x-1=0 \\ \Rightarrow 2 \sin ^{2} x+2 \sin x-\sin x-1=0 \\ \Rightarrow 2 \sin x(\sin x+1)-1(\sin x+1)=0 \\ \Rightarrow(2 \sin x-1)(\sin x+1)=0 \\ \therefore \sin x=\frac{1}{2}=\sin \frac{\pi}{6}=\sin \left(\pi-\frac{\pi}{6}\right) \\ \therefore x=\frac{\pi}{6}, \frac{5 \pi}{6} \end{array}$