MATHEMATICS · Single correct · AP · Calculus AB · Differentiation: Composite, Implicit, and Inverse Functions · Differentiation: Composite, Implicit, and Inverse Functions
Problem
If f(x)=cot−1(1−3x23x−x3) and g(x)=cos−1(1+x21−x2), then x→alimg(x)−g(a)f(x)−f(a), where 0<a<21, is
(a) 2(1+a2)3
(b) 2(1+x2)3
(c) 23
(d) −23