MATHEMATICS · Subjective · AP · Calculus BC · Infinite Sequences and Series · Infinite Sequences and Series
Problem
The series expansion for arctanx on ∣x∣≤1 is x−3x3+5x5−⋯. Using only the cubic polynomial x−3x3, determine all real numbers x in the interval [0,1] for which the magnitude of the remainder is less than 0.01. Give the largest such value of x correct to two decimal places.