Consider the parametric equations
x=t3−3t2,y=t2−2t,−2≤t≤3.
Let I be the set of x-values satisfying −1≤x≤1.
(a) Determine the corresponding set of t-values that map into I. Present your answer as one or more intervals.
(b) On each t-interval found in part (a), evaluate the sign of dx2d2y. Show analytical work supporting each sign determination.
(c) State the x-intervals over which the curve is concave up and the x-intervals over which it is concave down, restricted to I. Justify your conclusions.