[?] Plot multiple functions (2D and 3D)?

Questions
1

Hi!

I can’t get the graphing functions to quite work.
I want to plot three simple functions that look something like this:

x^2+2y-3z=8, x+y=10, 3z+7y=20

And I want to show them in both 2D and 3D graphs where they intersect, (ex: in x=3, y=8, z=10), how do I do that?

I was looking at the Plot and LogPlot command, but I am not quite sure I am looking at the right place

2

You will need ContourPlot and ContourPlot3D, there are a bunch of examples in the documentation. Copy paste and you’re good to go.

3

There is no solution in real domain for the three equations, and the intersection point you give is incorrect as can be easily seen by checking the second equation; i.e. 3 + 8 != 10.

For plotting, I think Sander gives excellent advice on showing the three surfaces.