Can you explain what do you mean by "twins", please?
He mean the Negative Point.
The curve is like a mirror, in the X axis, every X value have two Y values.
I don't think that's what he meant! It had the form u-these points have the same coordinate "Y" - as the points Y-
Y= 483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8