MATHEMATICS · Multi-part · AP · Calculus AB · Analytical Applications of Differentiation · Analytical Applications of Differentiation
Problem
A closed curve is defined implicitly by 2x2+3y2=12x+18.
(1) Compute dxdy in terms of x and y. Present your work.
(2) Compute dx2d2y in terms of x and y. Simplify your expression.
(3) The upper half of the curve (where y>0) can be written locally as y=g(x). Determine the intervals of x on which this upper half is concave up and the intervals on which it is concave down. Express your final answer in interval notation and justify by analyzing the sign of dx2d2y.