How do I get both branches (i.e. positive and negative values) for f(x) on the same plot of f(x) = x^(1/2)?

Thanks very much,

Greg

I'm trying to get a plot of f(x)=x^1/3 that shows the plot line (i.e. f(x) values) for x<0.  I can get the graph to show the entire four quadrants, but not plot the values for x<0.  Any help would be greatly appreciated, as I just purchased the student edition.

Thanks!