MATHEMATICS · Single correct · AP · Calculus BC · Parametric, Polar, and Vector-Valued Functions · Parametric, Polar, and Vector-Valued Functions
Problem
Consider the curve G given by r=cosθ for −2π≤θ≤2π. Let A1 be the area generated as θ varies from −2π to 0, and let A2 be the area generated as θ varies from 0 to 2π. Which statement best justifies the relationship between A1 and A2?
(a) A1<A2 because cosθ decreases on the interval −2π≤θ≤2π.
(b) A1>A2 because the part of the curve traced for negative θ produces an additional region below the x-axis.
(c) A1=A2 because (cosθ)2 is an even function of θ.
(d) No comparison can be made since r is negative for some values of θ in the interval.