I used "search" by typing "tex" but only find a thread, it seems to said that by using [tex]...[/tex] , you can type formula well.(adsbygoogle = window.adsbygoogle || []).push({});

So I tried this and preview the post, but it was not valid, and I was confused.

I just typed like below,thx:

[tex]

\nabla(\bf{x}\cdot

\bf{a})=\bf{a}+\bf{x}(\nabla\cdot\bf{a})+i(\bf{L}\times\bf{a})

\ \

where \ \ \bf{L}={\frac{1}{i}}(\bf{x}\times\nabla)

[/tex]

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# How to type formula in tex at PF?

**Physics Forums | Science Articles, Homework Help, Discussion**