12

Unfortunately I'm not able to provide a MWE, because this error apparently is not reproduceable in another document

As you can see in the picture, the upper sqrt is somehow tilted...

There is nothing in the log related to this part.

Any idea, what this could be?

\documentclass[
titlepage,
12pt,
a4paper,
parskip=half,
oneside,
%   bibtotoc,
%   listof=nochaptergap,
final  % Status des Dokuments (final/draft)
]{scrbook}

\usepackage[T1]{fontenc}
\usepackage{lmodern}
\usepackage[ngerman]{babel}
\usepackage{amsmath} %Mathe Umgebung

\begin{document}

\begin{align}
I_{max}&=  \sqrt{\dfrac{P_{nom}-\frac{P_{nom}}{T_{max}-T_{nom}}
\cdot(T_{max}-T_{amb})}{R}} \label{gl:resis-power1}\\
I_{max}&= \sqrt{\dfrac{P_{nom}-\frac{P_{nom}}{155^\circ C-70^\circ C}\cdot(155^\circ C-T_{amb})}{R}} \label{gl:resis-power2}

\end{align}

\end{document}

enter image description here

Marcel
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    In the top example, the numerator is bigger because of the subscripts, so TeX has to choose a larger radical, which turns out to be the “composed” one, made up with vertical pieces. – egreg Nov 18 '16 at 09:20
  • i can't reproduce your result. both square root has equal shape. only top one is slightly taller. – Zarko Nov 18 '16 at 09:29
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    The radicals are as expected but note you should not use math italic for words such as max (unless they mean m times a times x) use _{\mathrm{max}} – David Carlisle Nov 18 '16 at 10:05
  • or simple \max :) – Zarko Nov 18 '16 at 10:08
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    @Zarko Unfortunately, \max is semantically wrong in this context. \max is a mathematical operator whereas the index \mathrm{max} is merely a descritpion, consider e.g. x_{\mathrm{max}} = \max_x f(x). – Henri Menke Nov 18 '16 at 10:15
  • @Marcel Could you please add a MWE or at least tell what document class (plus other options/commands to change the font size) you are using? I'm trying with different classes and font sizes, but I'm not able to reproduce your output. – siracusa Nov 18 '16 at 10:30
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    @HenriMenke, I agree that \max used for index is not semantically correct, but is appearance of x_{\max} differ from x_{\mathrm{max}}? – Zarko Nov 18 '16 at 10:45
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    @Zarko Yes, if \operator@font and \mathrm differ. – Henri Menke Nov 18 '16 at 12:36
  • @siracusa now I was able to produce a MWE :) – Marcel Nov 21 '16 at 07:35
  • Thanks guys for the hint, I'll try to improve my formulas in the future (I used to use \mathrm in the past, but I became to lazy after a while... ) – Marcel Nov 21 '16 at 07:38

1 Answers1

22

What you show is entirely expected. Math fonts have a fixed number of "designed" symbols in a range of sizes (where the left of the radical is sloped, and parentheses are curved). But then (depending on the font and the symbol being displayed) at some point there are no symbols of that size available and so it switched to a "constructed" symbol made up of glyph parts and a necessarily straight vertical extension symbol repeated as often as necessary.

enter image description here

In this case the subscript T_{\mathrm{nom}} in the numerator just fractionally increased the height of the fraction and forced Tex to switch the method of displaying the square root .

David Carlisle
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    At the bottom we see a nice visualization of the Doppler effect, as demonstrated by a tiny x travelling to the left while yelling the number 2. – Wojciech Morawiec Nov 18 '16 at 16:35