Posted by Linda on Sunday, June 17, 2012 at 3:30am.
This is not a straight line it is a parabola. You will need several points.
some are:
(0,0), (2,2), (2,-2), (8,4), (8, -4) , etc
(I picked an even number for y, then found the x)
plot these and see the general outline of your curve.