# 3D plot of two 2D functions

I would like to plot two 2d functions in a 3d coordinate system. Examples are z = x^2 and z = y^2. Each function has one independent variable, (either x or y), and a global dependent variable (z).

• You've seen Plot3D[] already? Apr 20, 2013 at 18:48
• yes, of course, but i would like to show two independent 2d functions, eg. z=x^2 and z=y^2 in a xyz coordinate system. Apr 20, 2013 at 18:56
• Then what's wrong with Plot3D[x^2+y^2,{x,-1,1},{y,-1,1}] ?
– Jens
Apr 20, 2013 at 18:58
• Well, Plot3D[{x^2, y^2}, {x, -2, 2}, {y, -2, 2}] works for me... Apr 20, 2013 at 19:02
• The Plot3D Argument merge these functions into one surface object, i would like to show them independent in, zy and zx layer. Apr 20, 2013 at 19:03

For the two curves use the command:

g1 = ParametricPlot3D[{{t, 0, t^2}, {0, u, u^2}}, {t, -10,10}, {u, -10, 10},
BoundaryStyle -> Thick];


in addition, if you want also to have the two $x-y$ and $y-z$ planes in the plot:

planes = ContourPlot3D[{x == 0, y == 0}, {x, -10, 10}, {y, -10, 10}, {z,0, 100},
Mesh -> False, ContourStyle -> {Directive[Blue, Opacity[0.4]],
Directive[Green, Opacity[0.4]]}];

Show[g1,planes,PlotRange->{All,All,{-10,10}}] • many, many thanks. that's what i am looking for! Apr 20, 2013 at 20:29
• @pauleck, if this answers your question you should click on the check mark and the up-arrow next to the answer (to up-vote it - as I just did...) If you still want to wait for other answers, it's OK to leave the check mark unchecked until a day or so later.
– Jens
Apr 20, 2013 at 21:03
• @Jens, OP has rep $1$; unless he is given rep (say, by upvoting his question), he won't be able to upvote Spawn's answer. He can certainly accept Spawn's answer, if it suits his needs. Apr 21, 2013 at 0:26