Forcing mathematica or geo sketch to graph EC

[heartless]

Hello, I'm trying to experiment with eliptic curves a little, but I have a problem with graphing elliptic curves. For example, neither mathematica nor geometry sketchpad graph negative values of curves. Is there anyway to force mathematica or geo sketchpad to plot also negative values of x?
F. ex, when I try to graph y=(x^3-x)^(1/2) it plots only positive values for function. Any ideas?

Thanks,

 

[HallsofIvy]

Well, how about doing two functions:y=(x^3-x)^(1/2) and
y=-(x^3-x)^(1/2)?

 

[Orion1]

Mathematica:
$$\text{Plot[} ((-\sqrt{x^3 - x}), (\sqrt{x^3 - x})) \text{, (x,-10,10)}]$$

Where the brackets '()' are actually '{}'.
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