MATHEMATICS · Multi-part · AP · Calculus AB · Differentiation: Definition and Fundamental Properties · Differentiation: Definition and Fundamental Properties
Problem
Consider the function
h(x)=3x+∣x∣,
which is defined for all real x.
(a) Show that h is continuous at x=0.
(b) For x=0, compute h′(x). Present your work separately for x>0 and x<0 if necessary.
(c) Evaluate x→0−limh′(x) and x→0+limh′(x).
(d) Does h have a tangent line at x=0? If not, explain which term of h is responsible for the failure of differentiability and characterize the type of nondifferentiable point observed.