How to put text below some text in an equation

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Please refer the attached image. I want to write \omega \in \mathbb below sup as shown in the equation in the image. How should I do it?

asked Nov 16, 2018 at 8:19 931 4 4 gold badges 13 13 silver badges 32 32 bronze badges

1 Answer 1

For what you want:

Er=\sup_<\omega\in\mathbb>||G(j\omega)-R(j\omega)||_\infty

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If you want to put arbitrary text (or anything) below some other text (or anything you want) generally you can use \underset<><> and \mathop<> like this

%\usepackage \underset

\mathop_

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answered Nov 16, 2018 at 8:26 user156344 user156344

Combining \underset and \mathop is a little redundant: either \underset or \mathop_ would work, but for \lim -style operators \operatorname* is advisable (or you could put \DeclareMathOperator*<\Normal> in the preamble and then use \Normal ). Note that \underset , \operatorname and \DeclareMathOperator all require amsmath .

Commented Nov 16, 2018 at 10:11 (I just posted the answer because I use it :))) – user156344 Commented Nov 16, 2018 at 10:17

No problem. Your answer is good, but you should remove \mathop in the second code block (it effectively does nothing) and you might want to mention that you need to load amsmath to use \underset .

Commented Nov 16, 2018 at 10:30

@Circumscribe Actually I got it from Toogle TeX option of MathType one year ago when I am just a newbie to LaTeX. I always load amsmath package in all of my files, so I don't see any problem :) Thank you for give me more very useful knowledge!

– user156344 Commented Nov 16, 2018 at 10:40

Yeah, you'll probably always want to load amsmath if you're typesetting anything that that involves equations. While we're at it, it is better to use \| instead of || (because it is a single character), and better still to use \lVert and \rVert (also from amsmath ) because these have better spacing.