typing a straightline next to a dfrac?

Question

I would like to type enter image description here

how do I do it?

Thanks!

A.Ellett · Accepted Answer · 2013-09-02T00:52:40.667

1

Provided you've loaded the amsmath and amsfonts packages, you can write something like

\[
  \left. 
    \frac{\mathrm{d}\mathbb{P}^{\beta}}
         {\mathrm{d}\mathbb{P}} 
  \right|_{\mathcal{F}_t}
\]

enter image description here

\left and \right allows you to using grouping-like symbols and resize them to match the height of the material bracketed. In this case, you only have | which is not paired with anything else. So we use \left. to fill in for the missing grouping symbol.

Regarding \[...\], this is for displayed math expressions. It is currently preferred over $$...$$ as it handles various spacing issues better, among other things.

edited Sep 02 '13 at 00:52

answered Sep 02 '13 at 00:41

A.Ellett

50,533

I trust you that this works and i will use it but can i ask how exactly does this make the | long? – Lost1 Sep 02 '13 at 00:42
you want the t outside the mathcal – Lost1 Sep 02 '13 at 00:44
also what is [ ]? never used this before – Lost1 Sep 02 '13 at 00:44

typing a straightline next to a dfrac?

1 Answers1