Question
Prove that $\ce{cosec} \ \theta  \sqrt{1-\cos ^2 \theta}=1$

Answer

$\text { L.H.S }=\operatorname{cosec} \theta \times \sqrt{1-\cos ^2 \theta}$
$=\operatorname{cosec} \theta \times \sqrt{\sin ^2 \theta}   \ldots\left[\begin{array}{l}\because \sin ^2 \theta+\cos ^2 \theta=1 \\ \therefore 1-\cos ^2 \theta=\sin ^2 \theta\end{array}\right]$
$=\operatorname{cosec} \theta \times \sin \theta$
$=1 \ldots \ldots[\because \sin \theta \times \operatorname{cosec} \theta=1]$
$=\text { R.H.S }$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free