I am trying to graph the cube root of x, but when I do as

plot(x^1/3,thickness=5)

I get a graph with domain of non negative reals.  I need the entire graph, across all reals and I'm not sure how to handle it.  Thanks

I want to graph y=x^2, x>=0. but i want the axis to go from -2..2 so that you can see the restriction.  How do I go about this?