Well for part (a) since the equation of a slope is then the expression should be right?You can find the slope of the tangent line to a parabola at a point using the following method.
(a) Find an expression, in terms of x and a, for the slope of a secant line from to another point on the parabola.
(b) Simplify this slope assuming . What number, in terms of , does this quantity approach as approaches ?
I don't understand part (b) at all.