Which of the following series diverges based solely on the behavior of its th term?

MATHEMATICS · Single correct · AP · Calculus BC · Infinite Sequences and Series · Infinite Sequences and Series

Problem

Which of the following series diverges based solely on the behavior of its

n

th term? (a)

\displaystyle \sum_{n=1}^{\infty}\frac{1}{\sqrt n}

(b)

\displaystyle \sum_{n=1}^{\infty}\frac{(-1)^n}{n}

(c)

\displaystyle \sum_{n=1}^{\infty}\frac{n+1}{2n}

(d)

\displaystyle \sum_{n=1}^{\infty}\frac{1}{n}