Answer
1
Work Step by Step
By identity, $csc\theta=\frac{1}{sin\theta}$
$$=\frac{1}{sin^{2}\theta}\times(1-cos^{2}\theta)$$
By identity, $sin^{2}\theta+cos^{2}\theta=1$ (Rearrange and replace 1-$cos^{2}\theta$ with $sin^{2}\theta$,
$$=\frac{sin^{2}\theta}{sin^{2}\theta}=1$$