Fundamental Theorem and Maxima

[flyingpig]

Homework Statement

Si(x) = \int_{0}^{x}{\frac{sin(t)}{t} dt

At what values of x does this function have a local maximum?
2.Solutions

[PLAIN]http://img833.imageshack.us/img833/701/27444263.png

The Attempt at a Solution

So I took the derivative and applying FTC and I got sin(x)/x = 0

sin(x) = 0

x=n\pi

Then I drew a number line and I got lost. I looked at the solutions and I was even more lost. This is due tomorrow please help

 

[flyingpig]

PF is confused too huh? lol