C-09-Q160mediumsingle_mcqcosec90∘=?\operatorname{cosec} 90^\circ = ?cosec90∘=?a000b111c∞\infty∞dundefinedব্যাখ্যাCosecant is the reciprocal of sine: cosec90∘=1sin90∘=11=1\operatorname{cosec}90^\circ=\dfrac{1}{\sin 90^\circ}=\dfrac{1}{1}=1cosec90∘=sin90∘1=11=1.