Everyone here loves to go on about it but what is it?
Why ?Originally posted by chroot
Calculus allows you to find this equation. For the parabola y=x^2, it happens that the slope is given by the equation m=2x. Thus at the point x=4, the slope is m = 2(4) = 8.
It's beyond the scope of this board to explain exactly why the slope of the parabola y=x^2 is m=2x, so I will refer you to any good calculus textbook.