平均能量损失

Question

以下输出看起来太密集了。你能让它在垂直和水平方向上都更松散一些吗？

平均能量损失

\documentclass[preview,border=12pt,12pt]{standalone}
\usepackage{amsmath,xcolor}
\let\temp\underbrace
\def\underbrace#1_#2{{\color{red}\temp{{\color{black}#1}}_{#2}}}

\begin{document}
$\displaystyle
\begin{aligned}
x^2+6x+10 
&= \underbrace{x^2}_{a^2} \underbrace{+2x (3)}_{+2ab} + 10\\
&= \underbrace{x^2}_{a^2} \underbrace{+2x (3)}_{+2ab} \underbrace{+(3)^2 -(3)^2}_{+b^2-b^2} +10\\
&= \underbrace{x^2+2x(3)+(3)^2}_{a^2+2ab+b^2}  -(3)^2 +10\\
&= \underbrace{(x+3)^2}_{(a+b)^2} -9 +10\\
&= (x+3)^2+1
\end{aligned}
$
\end{document}

我们随时欢迎任何建设性的建议、意见、想法等！

Answer 1

我会用\mathstrut它来涵盖最常见的避免幻影的情况；也比数学模式\textcolor更好。\color

您需要{}在前面添加+以获得合适的间距。我还添加了几个细空格来分隔括号。

\documentclass[border=12pt,12pt]{standalone}
\usepackage{amsmath,xcolor}

\let\latexunderbrace\underbrace
\def\underbrace#1_#2{%
  {\,\textcolor{red}{\latexunderbrace{\textcolor{black}{\mathstrut#1}}_{#2}}\,}%
}

\begin{document}
$\displaystyle
\begin{aligned}
x^2+6x+10 
&= \underbrace{x^2}_{a^2} \underbrace{{}+2x (3)}_{+2ab} + 10\\
&= \underbrace{x^2}_{a^2} \underbrace{{}+2x (3)}_{+2ab} \underbrace{+(3)^2 -(3)^2}_{+b^2-b^2} +10\\
&= \underbrace{x^2+2x(3)+(3)^2}_{a^2+2ab+b^2}  -(3)^2 +10\\
&= \underbrace{(x+3)^2}_{(a+b)^2} -9 +10\\
&= (x+3)^2+1
\end{aligned}
$
\end{document}

略微好一点的版本，删除了 + 前面的空格

\documentclass[border=12pt,12pt]{standalone}
\usepackage{amsmath,xcolor}

\let\latexunderbrace\underbrace
\def\underbrace#1_#2{%
  {\,\textcolor{red}{\latexunderbrace{\textcolor{black}{\mathstrut#1}}_{#2}}\,}%
}
\newcommand{\hplus}{{\mspace{-\medmuskip}}+}

\begin{document}
$\displaystyle
\begin{aligned}
x^2+6x+10 
&= \underbrace{x^2}_{a^2} \underbrace{\hplus 2x (3)}_{+2ab} + 10\\
&= \underbrace{x^2}_{a^2} \underbrace{\hplus2x (3)}_{+2ab} \underbrace{+(3)^2 -(3)^2}_{+b^2-b^2} +10\\
&= \underbrace{x^2+2x(3)+(3)^2}_{a^2+2ab+b^2}  -(3)^2 +10\\
&= \underbrace{(x+3)^2}_{(a+b)^2} -9 +10\\
&= (x+3)^2+1
\end{aligned}
$
\end{document}

Answer 2

\documentclass[preview,border=12pt,12pt]{standalone}
\usepackage{amsmath,xcolor}
\let\temp\underbrace
\def\underbrace#1_#2{{\color{red}\temp{{\color{black}{\strut}#1{}}}_{#2}}}

\begin{document}
$\displaystyle
\openup1\jot
\begin{aligned}
x^2+6x+10 
&= \underbrace{x^2}_{a^2} \underbrace{+2x (3)}_{+2ab} + 10\\
&= \underbrace{x^2}_{a^2} \underbrace{+2x (3)}_{+2ab} \underbrace{+(3)^2 -(3)^2}_{+b^2-b^2} +10\\
&= \underbrace{x^2+2x(3)+(3)^2}_{a^2+2ab+b^2}  -(3)^2 +10\\
&= \underbrace{(x+3)^2}_{(a+b)^2} -9 +10\\
&= (x+3)^2+1
\end{aligned}
$
\end{document}

{}因此 + 获得中缀间距，添加后\strut括号就都处于相同的深度，并且添加后\openup行距会稍微增加。