Simplify sin(theta)csc(theta)-sin(theta)^2

$\sin (θ) \csc (θ) - \sin^{2} (θ)$

Rewrite in terms of sines and cosines, then cancel the common factors.

Reorder $\sin (θ)$ and $\csc (θ)$ .

$\csc (θ) \sin (θ) - \sin^{2} (θ)$

Rewrite $\sin (θ) \csc (θ)$ in terms of sines and cosines.

$\frac{1}{\sin (θ)} \sin (θ) - \sin^{2} (θ)$

Cancel the common factors.

$1 - \sin^{2} (θ)$

Apply pythagorean identity.

$\cos^{2} (θ)$