Answer
$0$
Work Step by Step
The trigonometric ratios are as follows: $\sin \theta= \dfrac{opposite}{hypotenuse}$ ; $\cos \theta= \dfrac{Adjacent}{hypotenuse}$ and $\tan \theta= \dfrac{Opposite}{Adjacent}$
Since,
$\sin \theta=\cos (90^{\circ}-\theta)$
So, $\cos \dfrac{\pi}{2}=\sin (\dfrac{\pi}{2}-\dfrac{\pi}{2})=\sin (0)=0$
Our required answer is: $0$
