All online graphers I could find could only compute lines whose equations were
$z=f(x,y)$
But what I'm looking for is
$y=f(x), z=g(x)$
So instead of $G_f=\{A(x,y,f(x,y))\}$ I need something like $G_{f,g}=\{A(x,f(x),g(x))\}$
I tried with surface plotters using the equation $(y-f(x))^2+(z-g(x))^2=0$ but it didn't work because, well, that equation doesn't represent a surface. Any help would be appreciated!