# Longer Cap of \sqrt

I am using ShareLaTeX for assignment.

I want to input an equation like:

$EOQ=Q^*=\sqrt(\frac{2K\lambda}{h})$


and got output like this:

But I really want the square root with longer cap (or roof? I am not sure how to call it, and therefore I am not able to search the solution) like this:

Wondering how I can fix that.

• \sqrt{\frac{2K\lambda}{h}}, not \sqrtsign(\frac{2K\lambda}{h}). Notice the braces. I don't think \sqrtsign is documented anywhere; if it is recommended in some manual, throw it away. – egreg Sep 22 '14 at 21:49
• Ahh... my bad, actually \sqrt also doesn't work... I will edit the post. – oldfatcrab Sep 22 '14 at 22:01
• Emphasis on @egreg s comment part Notice the braces you have parentheses. – percusse Sep 22 '14 at 22:04
• \sqrt{} should work. Could your limit your code to \documentclass{<something>}\usepackage{<somepackage>}\begin{document}$EOQ=Q^*=\sqrt{\frac{2K\lambda}{h}}$\end{document}? – 1010011010 Sep 22 '14 at 22:04
• Right, it is caused by the braces. Thank you both! – oldfatcrab Sep 22 '14 at 22:31

The \sqrt command takes as a mandatory argument what's to be extracted the square root of.

So the correct syntax is

\sqrt{a+b}


not \sqrt(a+b). Your problem is solved by using

Q^*=\sqrt{\frac{2K\lambda}{h}}


If you need the cube root (or other roots), there's the optional argument:

\sqrt[3]{a}


In a previous version of your question you had \sqrtsign: this macro actually exists for historical reasons, but is not documented and should not be used in documents.