which can again be approximated very well by a parabola. This happens for a simple reason that we typically take for granted: the Earth is made out of the same type of stuff, normal matter ...

If y = 4x + 3 is parallel to a tangent to the parabola y 2 = 12x, then its distance from the normal parallel to the given line is So, the slope of line is -4/3 So, the slope of normal to the line ...