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 $ $.

$\displaystyle \bullet$ 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

And viewed it by PDFviewer.Code:$\Gamma(s)=\int \limits_0^{\infty} e^{-t} t^{s-1} ~ dt$

$\displaystyle \bullet$ The size is too small ! Especially the integral sign. How can I change it ?

$\displaystyle \bullet$ Is it possible to modify a pdf that is already existing ?

$\displaystyle \bullet$ And what is DVI ?

$\displaystyle \bullet$ Is there a specific font you would advice me ?

$\displaystyle \bullet$ 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 !