Scaling 2D graphs in Mathematica

[TSN79]

Using Mathematica, does anyone know how to scale the axis equally in 2D graphs so that the grid formes perfect squares?

 

[LENIN]

I would do it by changing the AspectRatio (I think it's called that (look it up with Options[Plot])) from 1/GoldenRatio to 1 and maybe also use the PlotRange (or PlotRegion I can never remeber which is which). This will certanely help, but there might also be other more elegent solutions I don't know about.