my problem is that I need a way to quickly check results of my, that is to say, homework. I think that the best way to do this is to draw a plot of a function to quickly see whether my solution is correct. Up until I began to study 3D vector calculus everything was fine: it is possible to draw a 2d plot even in Google search tool. But recently I ran into necessity to draw 3d plot. And even the most elementary functions like
$$
y + 5 = 0
$$
(the plane parallel to the $oxz$ plane), or
$$
x + 3y = 0
$$
turned out to be very complicated to draw. I tried Mathematica, gnuplot, kalgebra. None of these helped me.
So I'm asking for an advice of software which allows to quickly draw a function plot in 2d and 3d with the simplest command line or GUI.
Or if no such soft exists, could anyone provide an example of how to draw plots of the functions mentioned above in tools like Mathematica or gnuplot.
Thank you.
Best Answer
Although this is a late answer neverthless it may be useful for some other readers.
I would recommend Geogebra which is a dynamic mathematics software for learning and teaching mathematics. It is also open source software.
3D properties have been added to geogebra version 5. You can easily create 3D objects like pyramids, prisms, spheres, cylinders, cones ... or you can draw graphics of multivariable functions of the form $f(x,y)$ simply.
For example from View->3D Graphics
in command line, type $f(x,y)=x^2+y^2$
or type $y=-5 $ for plane graph
You can explore the rich properties of Geogebra in time.