# Math Help - Cesaro Sum Help

1. ## Cesaro Sum Help

I apologize if this is in the wrong subject, but it is for my calculus class.

(a) Let $a_n >= 0, n \in N$ Let $s_n = a_1 + a_2 + · · · a_n$, i.e., partial sums of $\sum a_n$ from n = 1 to infinity.

Furthermore, let

$\tau_n = \frac{s_1 + s_2 + ... + s_n}{n}$ $, n \in N.$

Prove:

If $lim s_n = s$ then $lim \tau_n = s$ as well.

(b) The $\tau_n$ are called Cesaro sums, and the process is called Cesaro summation. It is used when the original sequence converges slowly or when a series does not have convergent partial sums. For example the series:

$1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, . . .$

$s_n$ does not have convergent partial sums but $\tau$ does converge. Find the Cesaro limit ( $lim \tau_n$)
of the sequence.

2. I figured out how to do part b (compute the Cesaro sum), so now I only need help on

Prove:

If then as well.