LyX and MikTeX

Hi !

I've installed MikTex and then LyX.
I've seen in the tutorial that one can directly type the latex code. That is "click on the Tex symbol" and then there is a red box where I can type the formula.
However, in the tutorial, they're saying that if I type \gamma, it would produce the symbol and change color. But when I type it and then view it by DVI, I only get an error message, telling me to put the $ $.
Indeed it works if I put $\gamma$. But why ? Do I have to put $ $ every time I type a formula ?

Then, I tried to type

Code:

---

$\Gamma(s)=\int \limits_0^{\infty} e^{-t} t^{s-1} ~ dt$

---

And viewed it by PDFviewer.
The size is too small ! Especially the integral sign. How can I change it ?

Is it possible to modify a pdf that is already existing ?

And what is DVI ?

Is there a specific font you would advice me ?

They don't accept \mathbb{R} :( how can I do ?

The questions may sound stupid, but I'm just a noob when it comes to get used to a new program :(


Thanks in advance !

Code:

---

\documentclass[12pt]{article}
\usepackage{amssymb} %this is for \mathbb code
\begin{document}
$\Gamma(s)=\displaystyle\int \limits_0^{\infty} e^{-t} t^{s-1} ~ dt$ for $s\in\mathbb{R}$.
\end{document}

---

works with me in WinEdt 5.5.

the LateX button is for inserting raw code, in LateX you need to use the dollar signs to designate a formula.

LyX has a special keyboard shortcut for math formulas, just type command(control)-shift-M and that will insert a floating formula where you can intuitively enter formulas.

more math options can be found if you go to the 'insert' menu and select the 'math' submenu.

hope that helped!