Find the value of$$ sin(180^\circ - \theta) cos (90^\circ -\theta ) - cos (180^\circ - \theta) sin (90^\circ - \theta)$$.

$$ sin(180^\circ - \theta) cos (90^\circ -\theta ) - cos (180^\circ - \theta) sin (90^\circ - \theta)$$.

$$sin(180^\circ - \theta) = sin (\theta )$$

$$cos (90^\circ -\theta ) = sin (\theta )$$

$$cos (180^\circ - \theta) = -cos (\theta )$$

$$sin (90^\circ - \theta)= cos (\theta )$$

$$sin (\theta ) sin (\theta )- -cos (\theta )cos (\theta )$$

$$sin (\theta ) sin (\theta )+cos (\theta )cos (\theta )$$ = 1