latex-miscmath-mode
In almost every application I've ever seen that uses math equations, it always supports LaTeX.
If LaTeX does so much more than just math equations, why is it the defacto standard for math equations? Isn't that akin to everyone deciding to use Microsoft Word's Math Editor for math equations?
Related question: Is there a name for the subset of LaTeX that deals specifically with math equations?
The mathtools package has a feature only to show the equation number for equations that are actually referenced, which seems to be what you are asking for.
However let me advise you against this, as a matter of style. Just because you don't refer to one of your equations, doesn't mean that your readers won't. It's extremely annoying as a user of a mathematical document to have to discuss with your colleagues "the 3rd unnumbered equation on page 42", or whatever, and there is really no harm in having a number for every equation in the document.
This is what I get from this simple example:
\documentclass[11pt,a5paper,footinclude=true,headinclude=true]{scrbook}
\usepackage[T1]{fontenc}
\usepackage[linedheaders,parts,pdfspacing]{classicthesis}
\begin{document}
This is inline math $a+b=c$ and a displayed formula follows:
\[
\int_{-\infty}^{\infty}e^{-x^2}\,dx=\sqrt{\pi}
\]
\end{document}
The font used for math is MathPaZo, which is tailored to accompany the default Palatino text font.
If I change the example in the following way
\documentclass[11pt,a5paper,footinclude=true,headinclude=true]{scrbook}
\usepackage[T1]{fontenc}
\usepackage[linedheaders,parts,pdfspacing,eulermath]{classicthesis}
\begin{document}
This is inline math $a+b=c$ and a displayed formula follows:
\[
\int_{-\infty}^{\infty}e^{-x^2}\,dx=\sqrt{\pi}
\]
\end{document}
(note the eulermath option), I get Euler Math for the formulas.
If instead you load lmodern after classicthesis
\documentclass[11pt,a5paper,footinclude=true,headinclude=true]{scrbook}
\usepackage[T1]{fontenc}
\usepackage[linedheaders,parts,pdfspacing]{classicthesis}
\usepackage{lmodern}
\begin{document}
This is inline math $a+b=c$ and a displayed formula follows:
\[
\int_{-\infty}^{\infty}e^{-x^2}\,dx=\sqrt{\pi}
\]
\end{document}
you get the "standard" LaTeX fonts
Best Answer
I think it's a survival of the fittest thing. First of all, math notation isn't specific to LaTeX, it's inherent in the TeX engine.
So what do we have:
I don't know what
troffdid for formulas (which might have been a competitor at the time), and I don't know whether Knuth invented it all by himself (was'nt there a system namedscribehe used as a blueprint?), but I can imagine there was not that much pressure to ever develop an alternative aspiring for all these features at once.You can look at MathML for the result what happens when such a thing is attempted by a committee ;-)