# Writing enlarged fractional exponents

I'm not able to write enlarged fractional exponents. For that purpose, '\frac' gives too small exponents, and '\dfrac' gives too large ones.

$x^{\dfrac{12}{7}}-x^{\dfrac{5}{7}}$

This yields:

But I want slightly better positioned exponents, like:

How can I do that?

• Welcome! Do you think that this would be clearer to a reader than x^{12/7}? – egreg Mar 16 at 18:07
• If you don't like either sizes, then may be you can adjust the font size manually, i.e. use '\small' or '\large' commands before the fraction exponent. – hesham Mar 16 at 18:08
• @hesham erh, no, you cannot use \small in math mode. You need to use trickery like what Steven shows. – daleif Mar 16 at 18:10
• Thanks @daleif. You're right. Then what about using \scalebox? – hesham Mar 16 at 18:13
• @hesham \scalebox switches to text, so no much different than Stevens solution – daleif Mar 16 at 18:15

\documentclass{article}
\abovebaseline[-1pt]{\hbox{\small$\dfrac{#1}{#2}$}}}
$x^{\specfrac{12}{7}}-x^{\specfrac{5}{7}}$

If I change \small to \scriptsize, then