draw graph of 1+x-[x]=y
where[x]=greatest integer function
Well, I like to think that you observed $\displaystyle y \in [1, 2)$.
Now, give x some values and see what happens. You can take z=x-[x] $\displaystyle \in [0, 1)$.
f(x)=1+{x} is periodical with T=1, so you can draw the graph for $\displaystyle x \in [0,1)$.