MATHEMATICS · Multi-part · AP · Calculus AB · Differentiation: Definition and Fundamental Properties · Differentiation: Definition and Fundamental Properties
Problem
Define p(x)=x2sinx+3x+1 for all real numbers.
(a) Verify that p is continuous for all real x and, in particular, at x=−1.
(b) Derive an explicit expression for p′(x) for x=−1.
(c) Evaluate x→−1limp′(x) by carefully justifying each step. Address any potential indeterminate forms that arise.
(d) Decide whether p is differentiable at x=−1. If not, describe the nature of the non-differentiability and give a geometric interpretation involving the tangent line (or lack thereof).
(e) Discuss how adding the term x2sinx alters, or does not alter, the differentiability properties inherited from 3x+1 at x=−1. Provide supporting mathematical evidence.