Let (f(x)= _ n=1 ^ (-1)^ ,n+1 x^ n n ) for (|x|<1 )

MATHEMATICS · Subjective · AP · Calculus BC · Infinite Sequences and Series · Infinite Sequences and Series

Problem

Let

f(x)=\displaystyle\sum_{n=1}^{\infty}(-1)^{\,n+1}\frac{x^{n}}{n}

for

|x|<1

. Approximate

f(0.2)

by evaluating the first three nonzero terms of the series and give your answer to four decimal places.