[Tex/LaTex] the difference between \dfrac and \frac

amsmathmath-mode

The title says it all, both \dfrac{a}{b} and \frac{a}{b} make fractions, so what is the difference between the two?

Best Answer

Mainly it's a difference of size:

  • \dfrac means that the fraction is set in displaystyle

  • \tfrac means that the fraction is set in textstyle

  • with \frac: the actual context implies the decision above

For example, if you have a complicated mathematical expression in the middle of some array environment (which, by default, employs text-style math), you can use \dfrac to force the use of displaystyle math mode for the fraction

\dfrac and \tfrac are from the amsmath package

Aside: TeX provides four math "styles": display style, text style, script style, and scriptscript style. scriptstyle is generally meant for level-1 subscripts and superscripts, and scriptscriptstyle is for level-2 subscripts and superscripts.