- #1

FaraDazed

- 347

- 2

## Homework Statement

Evaluate:

A: [itex]\sum_{n=1}^{\infty} 3^{\frac{n}{2}}[/itex]

B: [itex]\sum_{n=1}^{99} (-1)^n[/itex]

## Homework Equations

## The Attempt at a Solution

Really not sure how to show this in the proper mathmatical context so any help or advice is really much appreciated.

A:

[tex]\sum_{n=1}^{\infty} 3^{\frac{n}{2}}=1+\frac{1}{\sqrt{3}}+\frac{1}{3}+0.192+\frac{1}{9}[/tex]

This looks as though the limit is 2, as n tends to infinity

B:

[tex]

\sum_{n=1}^{99} (-1)^n=1-1+1-1+1-1

[/tex]

I noted that when n is even it is +1 and when it is odd it is -1 and since 99 is odd, then the limit is 0 as n tends to 99.