# Move horizontal bar in fraction lower

In the picture I have below, the numerator is dense with terms but the denominator only has one term. Thus, it would be nice to shift the horizontal bar lower to save space and look nice. I have no idea how to do it and could not find any information on it anywhere else.

my code :

\begin{equation*}
\Rightarrow \alpha \mathlarger{\mathlarger{\sum}}_{c}A_c a_k\left( \frac{
\scalemath{0.85}{
\begin{aligned}
\underbrace{\left[\left(\sum_{k=1}^{\nu-1}\frac{a_k}{12}(y_k^2+y_k y_{k+1} +y_{k+1}^2)\right) - \lambda_1\right]^2}_{\mathlarger{\mu_1}} +
\underbrace{\left[\left(\sum_{k=1}^{\nu-1}\frac{a_k}{24}(x_k y_{k+1}+2x_ky_k+2x_{k+1}y_{k+1} +x_{k+1}y_k)\right) - \lambda_2 \right]^2}_{\mathlarger{\mu_2}} + \\[1em]
\underbrace{\left[\left(\sum_{k=1}^{\nu-1}\frac{a_k}{24}(x_k y_{k+1}+2x_ky_k+2x_{k+1}y_{k+1} +x_{k+1}y_k)\right) - \lambda_3 \right]^2}_{\mathlarger{\mu_3}}+
\underbrace{\left[\left(\sum_{k=1}^{\nu-1}\frac{a_k}{12}(x_k^2+x_k x_{k+1} +x_{k+1}^2)\right) - \lambda_4 \right]^2}_{\mathlarger{\mu_4}}
\end{aligned}
}
}
{\Lambda^2}
\right)
\end{equation*}


• Welcome to LaTeX! Welcome to TeX.SX! I'm sure someone will come with a solution for that, but curiously, why not take the 1/\Lambda^2 term outside of the brackets entirely? Mar 22 '16 at 11:06

I propose an alternative presentation.

\documentclass{article}
\usepackage{amsmath,relsize,graphicx}
\newcommand\scalemath[2]{\scalebox{#1}{\mbox{\ensuremath{\displaystyle #2}}}}
\begin{document}
\begin{equation*}
\Rightarrow \alpha \mathlarger{\mathlarger{\sum}}_{c}A_c a_k\left( \frac{
B
}
{\Lambda^2}
\right)
\end{equation*}
where
\begin{equation*}
\begin{aligned}
B = &\underbrace{\left[\left(\sum_{k=1}^{\nu-1}
\frac{a_k}{12}(y_k^2+y_k y_{k+1} +y_{k+1}^2)\right) -
\lambda_1\right]^2}_{\mathlarger{\mu_1}} +\\[1ex]&
\underbrace{\left[\left(\sum_{k=1}^{\nu-1}\frac{a_k}{24}(x_k y_{k+1}+
2x_ky_k+2x_{k+1}y_{k+1} +x_{k+1}y_k)\right) - \lambda_2 \right]^2}
_{\mathlarger{\mu_2}} + \\[1ex]&
\underbrace{\left[\left(\sum_{k=1}^{\nu-1}\frac{a_k}{24}(x_k y_{k+1}+
2x_ky_k+2x_{k+1}y_{k+1} +x_{k+1}y_k)\right) - \lambda_3 \right]^2}
_{\mathlarger{\mu_3}}+\\[1ex]&
\underbrace{\left[\left(\sum_{k=1}^{\nu-1}\frac{a_k}{12}(x_k^2+x_k x_{k+1} +x_{k+1}^2)\right) - \lambda_4 \right]^2}_{\mathlarger{\mu_4}}
\end{aligned}
\end{equation*}
\end{document}


Here is another way:

\documentclass{article}
\usepackage{amsmath,relsize,graphicx}
\newcommand\scalemath[2]{\scalebox{#1}{\mbox{\ensuremath{\displaystyle #2}}}}
\begin{document}
\begin{equation*}
\begin{aligned}
\Rightarrow \alpha \mathlarger{\mathlarger{\sum}}_{c}A_c a_k =
\frac{1}{\Lambda^2}\Biggl\{
&\underbrace{\left[\left(\sum_{k=1}^{\nu-1}
\frac{a_k}{12}(y_k^2+y_k y_{k+1} +y_{k+1}^2)\right) -
\lambda_1\right]^2}_{\mathlarger{\mu_1}} +\\[1ex]&
\underbrace{\left[\left(\sum_{k=1}^{\nu-1}\frac{a_k}{24}(x_k y_{k+1}+
2x_ky_k+2x_{k+1}y_{k+1} +x_{k+1}y_k)\right) - \lambda_2 \right]^2}
_{\mathlarger{\mu_2}} + \\[1ex]&
\underbrace{\left[\left(\sum_{k=1}^{\nu-1}\frac{a_k}{24}(x_k y_{k+1}+
2x_ky_k+2x_{k+1}y_{k+1} +x_{k+1}y_k)\right) - \lambda_3 \right]^2}
_{\mathlarger{\mu_3}}+\\[1ex]&
\underbrace{\left[\left(\sum_{k=1}^{\nu-1}\frac{a_k}{12}(x_k^2+x_k x_{k+1} +x_{k+1}^2)\right) - \lambda_4 \right]^2}_{\mathlarger{\mu_4}}\Bigg\}
\end{aligned}
\end{equation*}
\end{document}


The OP still would like to place it in a single presentation. I strongly recommend against this approach, but here might be a way:

\documentclass{article}
\usepackage{amsmath,relsize,graphicx,scalerel}
\newcommand\scalemath[2]{\scalebox{#1}{\mbox{\ensuremath{\displaystyle #2}}}}
\begin{document}
\begin{equation*}
\Rightarrow \alpha \mathlarger{\mathlarger{\sum}}_{c}A_c a_k
\vcenter{\hbox{\scaleleftright[2ex]{(}{ \frac{ \scalemath{0.85}{ \begin{aligned} \underbrace{\left[\left(\sum_{k=1}^{\nu-1}\frac{a_k}{12}(y_k^2+y_k y_{k+1} +y_{k+1}^2)\right) - \lambda_1\right]^2}_{\mathlarger{\mu_1}} + \underbrace{\left[\left(\sum_{k=1}^{\nu-1}\frac{a_k}{24}(x_k y_{k+1}+2x_ky_k+2x_{k+1}y_{k+1} +x_{k+1}y_k)\right) - \lambda_2 \right]^2}_{\mathlarger{\mu_2}} + \\[1em] \underbrace{\left[\left(\sum_{k=1}^{\nu-1}\frac{a_k}{24}(x_k y_{k+1}+2x_ky_k+2x_{k+1}y_{k+1} +x_{k+1}y_k)\right) - \lambda_3 \right]^2}_{\mathlarger{\mu_3}}+ \underbrace{\left[\left(\sum_{k=1}^{\nu-1}\frac{a_k}{12}(x_k^2+x_k x_{k+1} +x_{k+1}^2)\right) - \lambda_4 \right]^2}_{\mathlarger{\mu_4}} \end{aligned} } } {\Lambda^2}} {)}}}
\end{equation*}
\end{document}


If one removes the \vcenter{\hbox{$ and $}} from the equation, then the large fraction will be shifted, so that the fraction's division line will remain on the math axis.

• this certainly bypasses that problem and looks better :) but would be also nice to learn how to do that if in case. Thank you for this presentation style :)
Mar 22 '16 at 11:08
• @hadik I have provided a 3rd way. Mar 22 '16 at 11:41
• hey thanks, Steven but i get error Undefined control sequence. <recently read> \scaleleftright
Mar 22 '16 at 11:51
• @hadik That is part of the scalerel package, which is loaded in the preamble.Latest version is v1.7 Mar 22 '16 at 11:59

I propose the following layout, based on the \splitfrac command, designed to handle such situations, \mathllap, both from mathtools, and the medmath command from nccmath (medium-sized formulae, ~80 % of \displaystyle) and the flalign* environment:

\documentclass{article}
\usepackage[showframe]{geometry} \usepackage{mathtools, nccmath, relsize}
\usepackage{graphicx} \newcommand{\scalemath}[2]{\scalebox{#1}{\begin{math} {#2} \end{math}}}

\begin{document}

\begin{flalign*}
⇒ α\mathlarger{\mathlarger{\sum}}_{c}A_c a_k × {} \\[-4ex]
& & & & &\mathllap{\frac{%
\medmath{\splitfrac{
\overbrace{\left[∑_{k=1}^{\nu-1}\frac{a_k}{12}(y_k²+y_k y_{k+1} +y_{k+1}²) - \lambda₁\right]²}^{\textstyle\mu₁} +
\overbrace{\left[∑_{k=1}^{\nu-1}\frac{a_k}{24}(x_k y_{k+1}+2x_ky_k+2x_{k+1}y_{k+1} +x_{k+1}y_k) - \lambda₂ \right]²}^{\textstyle\mu₂}}%
{\underbrace{\left[∑_{k=1}^{\nu-1}\frac{a_k}{24}(x_k y_{k+1}+2x_ky_k+2x_{k+1}y_{k+1} +x_{k+1}y_k) - \lambda₃ \right]²}_{\textstyle\mu₃}+
\underbrace{\left[∑_{k=1}^{\nu-1}\frac{a_k}{12}(x_k²+x_k x_{k+1} +x_{k+1}²) - \lambda₄ \right]²}_{\textstyle\mu₄}}}}
{\Lambda²}}
\end{flalign*}

\end{document}


• thanks for introducing the new commands. now, i can plan better to write long fractions :)