How to write this mathematical expression in Latex
I have no idea ..please help
\underbrace
\sqrt{144...4}
This should do it (load amsmath):
amsmath
\[\underbrace{111\dots 111}_{100 \text{ times}} \]
\underbrace? – egreg Feb 20 '18 at 16:27\sqrt{144...4}? – Werner Feb 20 '18 at 16:32