MATHEMATICS · Multi-part · AP · Calculus BC · Infinite Sequences and Series · Infinite Sequences and Series
Problem
Consider the function g defined for x>0 by g(x)=xlnx. The function is to be analyzed near x=1.
(a) Starting from a known Taylor series, write the first four nonzero terms of the Taylor series of lnx about x=1. Express each term in powers of (x−1).
(b) Use your result from part (a) to obtain the first four nonzero terms of the Taylor series of g about x=1. Simplify each coefficient.
(c) From your series in part (b), determine the exact values of g′′(1) and g(4)(1). Clearly indicate how each derivative is obtained from the series.