Answer
$y = 1-cot~x$
We can see the graph below.
Work Step by Step
$y = 1-cot~x$
When $x = 0$, then $y = 1-cot~0$ (which is undefined)
When $x = \frac{\pi}{4}$, then $y = 1-cot~\frac{\pi}{4} = 0$
When $x = \frac{\pi}{2}$, then $y = 1-cot~\frac{\pi}{2} = 1$
When $x = \frac{3\pi}{4}$, then $y = 1-cot~\frac{3\pi}{4} = 2$
When $x = \pi$, then $y = 1-cot~\pi$ (which is undefined)
We can see the graph below.