MATHEMATICS · Multi-part · AP · Calculus BC · Parametric, Polar, and Vector-Valued Functions · Parametric, Polar, and Vector-Valued Functions
Problem
Consider the parametric curve defined by x=t3−3t and y=t2−2t for t∈[−2,3]. Answer the following:
(i) Find dx2d2y in terms of t and simplify your result.
(ii) Determine all real values of t in the interval [−2,3] at which dx2d2y=0. For each such value, test the sign of dx2d2y immediately to its left and right.
(iii) Hence list the sub-intervals of t on which the curve is concave upward and those on which it is concave downward. State the coordinates of every point of inflection that lies on the curve in the given interval.