Calculators TI-89 won't graph whole function?

[amantonas]

When I try and graph x^(2/3) in my TI-89, it only graphs the half of the graph where x>0.
My TI-84 gives me this:

But my TI-89 only gives me the right half. Is one of my settings wrong?

 

[Greg Bernhardt]

Certainly sounds that way if the same function gives different results
http://www.wolframalpha.com/input/?i=x^(2/3)

 

[cbasst]

I believe that you can get the same graph given by the TI-84 by going into the "Mode" menu and selecting "Real" as the "Complex Format" type.