# Align and boxed don't work together

When I try to input:

\begin{eqnarray*}
w(t) &=& \frac{1}{2}Cv^2(t)\\
\boxed{w(t) &=& \frac{1}{2}C \frac{q(t)^2}{C^2}}\\
w(t) &=& \frac{1}{2}\frac{q(t)^2}{C}\\
w(t) &=& \frac{1}{2}Cv^2(t)\\
\end{eqnarray*}


I get an error. The following code works but the box is way of to the left... (I didn't use &=& on the boxed equation this time.)

\begin{eqnarray*}
w(t) &=& \frac{1}{2}Cv^2(t)\\
\boxed{w(t) = \frac{1}{2}C \frac{q(t)^2}{C^2}}\\
w(t) &=& \frac{1}{2}\frac{q(t)^2}{C}\\
w(t) &=& \frac{1}{2}Cv^2(t)\\
\end{eqnarray*}


Are there any ways to fix this issue?

Why no use \Aboxed command of the package mathtools? inside of an align* environment

\documentclass{article}
\usepackage{mathtools}
\begin{document}
\begin{align*}
w(t) &= \frac{1}{2}Cv^2(t)\\
\Aboxed{w(t) &= \frac{1}{2}C \frac{q(t)^2}{C^2}}\\
w(t) &= \frac{1}{2}\frac{q(t)^2}{C}\\
w(t) &= \frac{1}{2}Cv^2(t)\\
\end{align*}
\end{document}


• My editor doesnt want to import mathtools for some reason... – Rectifier Oct 13 '14 at 18:18
• What system do you use? OS? Tex distribution? Editor? – skpblack Oct 13 '14 at 18:24
• Win8, texmaker and the error I get is: 'mathtools.sly' not found – Rectifier Oct 13 '14 at 18:25
• MiKTeX or TeXLive? – skpblack Oct 13 '14 at 18:26
• You must install the mathtools package. If you use MiKTeX install from MiKTeX Package Manager. – skpblack Oct 13 '14 at 18:27