JEE Main 2019TrigonometryTrigonometric Ratio and IdentitesMediumQuestionThe value of (sin70∘)(cot10∘cot70∘−1)\left(\sin 70^{\circ}\right)\left(\cot 10^{\circ} \cot 70^{\circ}-1\right)(sin70∘)(cot10∘cot70∘−1) isOptionsA0B2/3C1D3/2Check AnswerHide SolutionSolutionsin70∘(cot10∘cot70∘−1)⇒cos(80∘)sin10=1\begin{aligned} & \sin 70^{\circ}\left(\cot 10^{\circ} \cot 70^{\circ}-1\right) \\ & \Rightarrow \frac{\cos \left(80^{\circ}\right)}{\sin 10}=1 \end{aligned}sin70∘(cot10∘cot70∘−1)⇒sin10cos(80∘)=1