# How do you find the 6 trigonometric functions for pi/2?

If P(x,y) submits $\alpha$ at the centre of unit circle, x = cos $\alpha$ , y = sin$\alpha$, tan$\alpha$ = y/x. etc.
For $\alpha$ = $\frac{\pi}{2}$ , x = 0, y = 1. $\implies$ cos$\frac{\pi}{2}$ = 0, sin$\frac{\pi}{2}$ = 1 and tan$\frac{\pi}{2}$= 1/0 (undefined)
csc$\frac{\pi}{2}$ = 1,sec$\frac{\pi}{2}$ = 1/0(undefined) and cot$\frac{\pi}{2}$ = 0.