# 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? – J. M.'s torpor Apr 20 '13 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. – pauleck Apr 20 '13 at 18:56
• Then what's wrong with Plot3D[x^2+y^2,{x,-1,1},{y,-1,1}] ? – Jens Apr 20 '13 at 18:58
• Well, Plot3D[{x^2, y^2}, {x, -2, 2}, {y, -2, 2}] works for me... – J. M.'s torpor Apr 20 '13 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. – pauleck Apr 20 '13 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! – pauleck Apr 20 '13 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 '13 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. – J. M.'s torpor Apr 21 '13 at 0:26