How to type formula in tex at PF?

[Dale12]

I used "search" by typing "tex" but only find a thread, it seems to said that by using $$...$$ , you can type formula well.
So I tried this and preview the post, but it was not valid, and I was confused.
I just typed like below,thx:


$$\nabla(\bf{x}\cdot \bf{a})=\bf{a}+\bf{x}(\nabla\cdot\bf{a})+i(\bf{L}\times\bf{a}) \ \ where \ \ \bf{L}={\frac{1}{i}}(\bf{x}\times\nabla)$$

 

[Moonbear]

Here's a thread where you can view other people's code and try your own (you're allowed to just practice using LaTex in it). It's a sticky thread in the General Physics forum in case you don't bookmark it and need to find it again later.

https://www.physicsforums.com/showthread.php?t=8997

 

[Dale12]

Here's a thread where you can view other people's code and try your own (you're allowed to just practice using LaTex in it). It's a sticky thread in the General Physics forum in case you don't bookmark it and need to find it again later.

https://www.physicsforums.com/showthread.php?t=8997

thanks, I just found it^_^. and before this, I found formula I type can be shown normally, it's glad to see this. but still there are two question:
1. it says that we use tex & /tex, but how to add [] in the beginning and the end to tell others or just show this as explanation , because they disapper as tags after u post them.
2. how to begin a second paragraph or how to type enter in formula here? I tried to insert "\\" before "where" above but failed.

 

[Dale12]

IC, thanks anyway!
1.Just add several spaces as [ tex ]...[ /tex ] .
2.add two [ tex ]...[ /tex ] can print as an "enter",maybe like below:


$$\nabla(\bf{x}\cdot\bf{a})=\bf{a}+\bf{x}(\nabla\cdot\bf{a})+i(\bf{L}\times\bf{a})$$
where
$$\bf{L}={\frac{1}{i}}(\bf{x}\times\nabla)$$

 

[quantumdude]

There's also another set of tags: [ itex ](stuff)[ /itex ]. The "i" stands for "inline", and it does just that: It lines the TeX up with the rest of your text. Check it out.

With [ tex ] tags:

The Lorentz factor in natural units is $$\gamma=\frac{1}{\sqrt{1-v^2}}$$.

And with [ itex ] tags:

The Lorentz factor in natural units is $\gamma=\frac{1}{\sqrt{1-v^2}}$.

 

[Lisa!]

https://www.physicsforums.com/showthread.php?t=8997
Why don't you make that a sticky thread in HW part too!?

 

[amcavoy]

https://www.physicsforums.com/showthread.php?t=8997
Why don't you make that a sticky thread in HW part too!?

Yeah that's definitely a good idea. Some posts are impossible to read without LaTeX!

Alex

 

[hotvette]

I found the following link helpful.

http://www.maths.tcd.ie/~dwilkins/LaTeXPrimer/

 

[quantumdude]

https://www.physicsforums.com/showthread.php?t=8997
Why don't you make that a sticky thread in HW part too!?

Yeah, then it can get ignored right along with the other sticky that's there (the one that says, "Read this before posting.")

Eh, maybe I'll make my own sticky that has the most commonly used equations in basic physics.

 

[Lisa!]

Yeah, then it can get ignored right along with the other sticky that's there (the one that says, "Read this before posting.")

Eh, maybe I'll make my own sticky that has the most commonly used equations in basic physics.

I read all your stickies! ( they're too long! )

You know Tom, you're too nice with kids in HW part. Whenever you see they don't use LaTex, you can simply post that sticky to them and ask them to learn how to use it. If you ask other HW helpers to do the same, you might be able to tackle this problem.

(Sometimes I think Greg should make a quiz about forum rules and using LaTex, and ask people to take it before registration. So only those people who can pass the test, would be allowed to post here! But I'm afraid they even don't get that they have to pass the test if they want to become a member here! :uhh:)