How to give another parameter in URL to plot a second graph?

[echteinfachtv]

As I found out we can use the URL to define a graph to be plotted, e.g. http://graph.tk/?x^2/5

This is great, but how can we assign a second graph within the URL? This does not work: http://graph.tk/?x^2/5&x^2

Thanks and have a good time, Kai