Answer
Refer to the sketch in the picture
Work Step by Step
$f(x,y)=y+1$
In order to draw the graph we need to know the number of independent variables (n), which will help us figure out the number of dimensions needed to draw the graph.
The function has two independent variables $x,y$
The dimension ($m$) = $n+1$
Hence we need three dimensions, that is, $x,y,z$
But the third dimension is the value of the function, that is, $z=y+1$
[NB: The value of $x$ does not have effect on the value of $z$]
We need a set of values of $y$ which will help us find z
The domain of the function = {$x,y∈R$}
$x,y$ can be any value
This information helps us to graph our function in three dimensions (x,y,z)
