Latex

[OldMan]

I cannot get latex to work. I type in stuff using [math]Let $f$ be the function defined by $f(x) = 3x + 7$, and let $a$ be a positive real number.[/math] or \begin{math} av=b/v \end{math} or \ensuremath{\alpha^2+\beta^2}.
No formatting when I hit "Preview".
When I use the given boxes above,

ax=b/v^2

, the preview looks different but not formatted.
I also cannot find "Forum Help" that I read in an earlier message I should refer to.
As always, any assistance is appreciated.
Thank you

 

[galactus]

On this forum, the tags are

[tex][/tex]

not [math][/math]

\(\displaystyle ax=\frac{b}{v^{2}}\)

\(\displaystyle {\alpha}^{2}+{\beta}^{2}\)

click on quote to see what code I used.

 

[OldMan]

Excellent. Thank you.