Remove space between left bracket and square root [duplicate]

I have a problem with removing the space between left bracket and multiple root square.

I use code

\documentclass{article}

\usepackage{amsmath}

\usepackage{letltxmacro}

\LetLtxMacro{\oldsqrt}{\sqrt}

\renewcommand{\sqrt}[2][]{\oldsqrt[#1]{#2}}

\begin{document}

$\left(\sqrt{3} \right)$ $\left(\sqrt[3]{4}\right)$

\end{document}


But only space in the left one got removed.

marked as duplicate by egreg spacing StackExchange.ready(function() { if (StackExchange.options.isMobile) return; $('.dupe-hammer-message-hover:not(.hover-bound)').each(function() { var$hover = $(this).addClass('hover-bound'),$msg = $hover.siblings('.dupe-hammer-message');$hover.hover( function() { $hover.showInfoMessage('', { messageElement:$msg.clone().show(), transient: false, position: { my: 'bottom left', at: 'top center', offsetTop: -7 }, dismissable: false, relativeToBody: true }); }, function() { StackExchange.helpers.removeMessages(); } ); }); }); Jun 17 '15 at 7:31

Maybe this would suffice. However, it does not (to my mind) work reasonable spacing in other circumstances (post square root), so I would prefer renaming it as \xsqrt or some unique name to be used sparingly.

RE-REVISED to take Heiko's suggestion on how to remove extra space following the square root:

\documentclass{article}
\usepackage{amsmath}
\usepackage{letltxmacro}
\LetLtxMacro{\oldsqrt}{\sqrt}
\renewcommand{\sqrt}[2][\mkern8mu]{\mkern-8mu\mathop{}\oldsqrt[#1]{#2}}
\begin{document}
$\left(\sqrt{3} \right)$ $\left(\sqrt[3]{4}\right)$

$x\sqrt{3} x\sqrt[3]{3}$

$y=\sqrt{3} = x = \sqrt[3]{2}$
\end{document}


REVISED:

\documentclass{article}
\usepackage{amsmath}
\usepackage{letltxmacro}
\LetLtxMacro{\oldsqrt}{\sqrt}
\renewcommand{\sqrt}[2][\mkern8mu]{\mkern-4mu\mathop{\oldsqrt[#1]{#2}}}
\begin{document}
$\left(\sqrt{3} \right)$ $\left(\sqrt[3]{4}\right)$

$x\sqrt{3} x\sqrt[3]{3}$

$y=\sqrt{3} = x = \sqrt[3]{2}$
\end{document}


• For the left side, \mathop{}\! before the root stuff can be used, then the right side remains unchanged regarding the horizontal spacing. – Heiko Oberdiek Jun 17 '15 at 4:29