Consider the function

MATHEMATICS · Multi-part · AP · Calculus BC · Infinite Sequences and Series · Infinite Sequences and Series

Problem

Consider the function g(x)=ln⁡(1+x)g(x)=\ln(1+x), which is analytic on (−1,1)(-1,1). The series is centered at a=0a=0 (Maclaurin), and you will approximate g(0.5)g(0.5) with a Taylor polynomial. (a) For xx in [0,0.5][0,0.5] and any integer k≥1k\ge 1, compute an explicit upper bound MM for ∣g(k)(x)∣|g^{(k)}(x)|. Express MM in a form that depends on kk, and justify why this bound is valid on the stated interval. (b) Derive an inequality that bounds the error ∣g(0.5)−Tn(0.5)∣|g(0.5)-T_{n}(0.5)|, where TnT_{n} is the nnth–degree Maclaurin polynomial. (c) Using the inequality from part (b), find the smallest integer nn that guarantees ∣g(0.5)−Tn(0.5)∣<10−6|g(0.5)-T_{n}(0.5)|<10^{-6}. Fully explain each step in solving the inequality for nn and verify that your chosen nn satisfies the required tolerance.

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