Question

Find the value of $\frac{cos({90}^{\circ }-\theta )cos\theta }{cot\theta }-1$

Answer 1

$\frac{\cos ({90}^{\circ }-\theta )\cos \theta }{\cot \theta }-1=\frac{\sin \theta \cos \theta }{\frac{\cos \theta }{\sin \theta }}-1={\sin }^2\theta -1=-{\cos }^2\theta$