# How can I make a ContourPlot3D with inequality constraints?

I need to plot a function in implicit form as below:

ContourPlot3D[{73.04 z*y^2 - 293.04 z*x^2 ==
2605.68 y^2 - 2605.68 x^2}, {x, 0, 3}, {y, 0, 6}, {z, 0, 15}]


but with the constraint x > y. How can I do this with Mathematica?

• How about ContourPlot3D[{73.04 z*y^2 - 293.04 z*x^2 == 2605.68 y^2 - 2605.68 x^2}, {x, 0, 3}, {y, 0, 6}, {z, 0, 15}, RegionFunction -> Function[{x, y, z}, x > y]] ? – Nasser Jun 14 '14 at 7:22
• @m_goldberg thank you for kindly editing my post again! :) – LCFactorization Jun 14 '14 at 7:51
• @Nasser: Just saw your comment (we must have been typing concurrently) - learned a new one - do you know if it's always the case you can truncate the supplied arguments from a given plot to your RegionFunction? (I've not tested this). That is, for CP3D, MM supplies 4 arguments to the function (I was surprised it "matched" a function with only 3 as in your comment), so I'm guessing it wraps the RegionFunction specified in a way that some arguments become optional. Thoughts? – ciao Jun 14 '14 at 23:02
• @rasher I just saw in help it used 3 arguments in the examples shown, and that is what I tried. !Mathematica graphics I did not know myself one can use 4 arguments like you did. – Nasser Jun 14 '14 at 23:08
• @Nasser: Ah! Interesting! In the help for RegionFunction itself, it explicitly shows four for CP3D et al. – ciao Jun 14 '14 at 23:12

Take a look at RegionFunction, e.g.:
ContourPlot3D[{73.04 z*y^2 - 293.04 z*x^2 == 2605.68 y^2 - 2605.68 x^2},