Take the 2-minute tour ×
TeX - LaTeX Stack Exchange is a question and answer site for users of TeX, LaTeX, ConTeXt, and related typesetting systems. It's 100% free, no registration required.

Is there a get around to make $\surd$ variable-sized via standard AMS package? For example, I would like $\surd \frac{a}{b}$ to look like $\sqrt{\frac{a}{b}}$ with the elongated left line but no overline on $\frac{a}{b}$.

share|improve this question
Welcome to TeX.SX! –  Christian Hupfer Aug 7 at 6:15
Hi! It's a nice question. However, from the perspective of math typography, such usage of this symbol is discouraged. It's preferable to always typeset the horizontal bar over the expression you make a root of: \[ \sqrt{\frac{a}{b}} \]. Another solutions for your example are: \[ \frac{\sqrt{a}}{\sqrt{b}} \] (that's what I prefer) or \[ \Bigl(\frac{a}{b}\Bigr)^{1/2} \]. –  yo' Aug 7 at 6:52
@tohecz Thank you for your reply. While I prefer the same style '$\sqrt{\frac{a}{b}}$' that you have suggested, my department is trying to adopt '$\surd$', which seems to be the standard notation for square root employed in Cambridge A-Level examinations. Thus, I am looking for ways to make the symbol '$\surd$' to match '$\sqrt$', minus the overline. –  user60342 Aug 7 at 8:19

2 Answers 2

Use the following definition:


and the test:

share|improve this answer

You probably want to have also the option of setting the root index; with xparse it's rather easy:






enter image description here

Of course, seeing the result I ask myself why a respected institution wants to change a long time honored notation.

share|improve this answer
This is the root of ugliness :-/ Especially the LHS. –  yo' Aug 7 at 8:54

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.