[Tex/LaTex] Integration with textstyle fractions limits

Question

I am trying to write an integration question like below with amsmath package:

\displaystyle\int_{\frac{\pi}{4}}^{\frac{\pi}{2}}\sin x\,\mathrm{d}x

However, the two fractions limits appear to be too small. I would like to do something like this:

\displaystyle\int_{\textstyle\frac{\pi}{4}}^{\textstyle\frac{\pi}{2}}\sin x\,\mathrm{d}x

Is there an efficient way to set all the integration limits in the document to \textstyle?

Answer 1

The only sensible way is to use \tfrac. Note the inconsistency in a common situation either with default or using \textstyle:

    \documentclass{article}
    \usepackage[utf8]{inputenc}
    \usepackage[T1]{fontenc}
    \usepackage{mathtools}

    \begin{document}

    Default:
    \[  \int_{k\frac{\pi}{4}}^{k\frac{\pi}{2}}\sin x\,\mathrm{d}x \]%
    \vskip 2ex
    With \verb+\tfrac+:
      \[ \int_{k\tfrac{\pi}{4}}^{k \tfrac{\pi}{2}}\sin x\,\mathrm{d}x  \]%
    \vskip 2ex
    With \verb+\textstyle+:
    \[  \int_{\textstyle k\frac{\pi}{4}}^{\textstyle  k\frac{\pi}{2}}\sin x\,\mathrm{d}x \]%

    \end{document}