Acrrcle has an initial radius of 50 ft when the radius begins decreasing at the rate of 3 ftimin. What is the rate in the change of area at the instant that the radius is 11 ft? Write an equation relating the area ofa circle, A, and the radius of the circle, r A21"2 (Type an exact answer, using II: as needed.) Differentiate both sides of the equation with respect tot dA _ 2 3 dr dt ' T" dt (Type an exact answer, using a: as needed, Type an expression using ras the variable) The rate of change of the area is ft2 (min, (Type an exact answer in terms of 1:)