Fatigue Analysis - Factor of safety

[Roomie]

Homework Statement

Hey everyone, I'm trying to do this question and have no idea where to go with it.

[PLAIN]http://dl.dropbox.com/u/630750/Screen%20Shot%202011-11-02%20at%2014.17.42.png

Homework Equations

See below.

The Attempt at a Solution

Here is my attempt/thinking so far.. http://dl.dropbox.com/u/630750/Photo%2002-11-2011%2014%2020%2014.jpg

Thanks for your help!

 

[Roomie]

Anybody?