i was just wondering how to do the symbol for a derivative and a double derivative, and the symbol for theta??
using LaTeX, type [tex]\frac{\,dy}{\,dx}[/tex] to get $\displaystyle \frac{\,dy}{\,dx}$, [tex]\frac{d^2y}{\,dx^2}[/tex] to get $\displaystyle \frac{d^2y}{\,dx^2}$, and [tex]\theta[/tex] to get $\displaystyle \theta$. However, I prefer [tex]\vartheta[/tex] to get $\displaystyle \vartheta$
You can find more tutorials and the such in the LaTeX Help part of the forums.
--Chris