Thread: tilde symbol under a variable

how do i "underline" x with a tilde (the ~ symbol)?

Originally Posted by wik_chick88

how do i "underline" x with a tilde (the ~ symbol)?

Don't know what you want, but:
[TEX]\underline{~x}[/TEX] or [TEX]\underline{\~x}[/TEX] or [TEX]\underline{\sim x}[/TEX] gives
or or

sorry, i realise how i worded it wrong. i want to put the ~ symbol underneath the x rather than on top of it

Originally Posted by wik_chick88

sorry, i realise how i worded it wrong. i want to put the ~ symbol underneath the x rather than on top of it

The tilde is placed on top of a symbol to indicate some special property. Why would you want to place it below a symbol?

well i want to specify that x is a vector. sometimes in my notes it has the ~ symbol underneath it, sometimes it is in bold (which i don't know how to do either)

Originally Posted by wik_chick88

well i want to specify that x is a vector. sometimes in my notes it has the ~ symbol underneath it, sometimes it is in bold (which i don't know how to do either)

The usual way to denote a vector v is \vec v, which yields .

Originally Posted by wik_chick88

sorry, i realise how i worded it wrong. i want to put the ~ symbol underneath the x rather than on top of it

[TEX]\mathop x\limits_ \sim [/TEX] gives

Originally Posted by wik_chick88

how do i "underline" x with a tilde (the ~ symbol)?

This is not easy in TeX. Part of the problem is that the tilde is a reserved character in TeX, which means that it is very hard to display it (except through the \tilde command, which produces an accent above a letter). The only way I can get it to appear underneath a character is to use Plato's idea in the previous comment, which produces something similar to a tilde by using the \sim symbol. The difficulty then is to get it to appear under an x, without raising the x, and without looking too big or too far underneath the x. The best I can manage is

[TEX]a \underset{^\sim}x b[/TEX]

which produces

.

Even then, the tilde is a long way below the x. I think you would probably do better to use an alternative notation.

Originally Posted by wik_chick88

well i want to specify that x is a vector. sometimes in my notes it has the ~ symbol underneath it, sometimes it is in bold (which i don't know how to do either)

Such notations are to denote a bold character in hand written material, more usual is an underscore. If you are setting stuff in LaTeX just make it bold.

CB

Originally Posted by CaptainBlack

Such notations are to denote a bold character in hand written material, more usual is an underscore. If you are setting stuff in LaTeX just make it bold.

CB

Which you can do on this forum by doing

[TEX]\mathbf{x}[/TEX], which renders

.