Plot points of elliptic curve

Question

I'm interested in plotting points of an elliptic curve over the real numbers. I'm looking to plot a few curves, but one like y^2 = x^3 + 7 would be an example of one. This is simple enough when x is positive, but when it's negative, I'm unsure how to find values. Are there any well-known algorithms for doing this?

Answer 1

Just plot the positive and negative roots:

Answer 2

Welcome to MSE! If you're familiar with programming, you can compute a list of points $(x,y)$ of the curve on your own. In view of the above curve, as Lord Shark said, real-valued points fulfill $x\geq -\sqrt[3]{7}$. Just loop over values $x$ and compute the $y$-values. Its easy with a computer algebra system like Maple.