减少大型数学方程式占用的空间

Question

我的文件中有几个大方程式，它们占用了很多空间。请帮我减小它们的大小。我已经尝试使用 \declaremathsizes，但它只会减小数学字体大小而不是占用的空间。这里给出了示例。

\documentclass[12pt,twocolumn,headings=normal]{article}
\usepackage{fullpage}
\usepackage{amsmath}
%\DeclareMathSizes{12}{1}{1}{1}
\begin{document}
this is the problem equation..
\begin{equation}
P^{bb}_{g}(n,p)=\begin{cases}
0, & \text{if $n=0$}.\\
0, & \text{if $n=1$}.\\
p*P^{bb}_{g}(n-1,p)+\\
(1-p)^2+p*(1-p) \\
*P^{bb}_{g}(n-2,p) , & \text{if $n \geq 2$}.\nonumber
\end{cases}
\end{equation}

i have many like this and it eats lot of space.

\end{document}

Answer 1

一个可能的解决方案。

代码

\documentclass[12pt,twocolumn,headings=normal]{article}
\usepackage{fullpage}
\usepackage{amsmath}
%\DeclareMathSizes{12}{1}{1}{1}
\begin{document}

\begin{equation*}
P^{bb}_{g}(n,p)=\begin{cases}
0, & \text{if $n=0~\&~1$}.\\
p*P^{bb}_{g}(n-1,p) +(1-p)^2 &\\ 
{}+p*(1-p) *P^{bb}_{g}(n-2,p) , & \text{if $n \geq 2$}.
\end{cases}
\end{equation*}

\end{document}

Answer 2

\documentclass[12pt,twocolumn,headings=normal]{article}
\usepackage{fullpage}
\usepackage{amsmath}
%\DeclareMathSizes{12}{1}{1}{1}
\begin{document}
this is the problem equation..

If $n \geq 2$ then
\begin{multline*}
P^{bb}_{g}(n,p)=*P^{bb}_{g}(n-1,p)+{}\\
(1-p)^2+p*(1-p) 
*P^{bb}_{g}(n-2,p)
\end{multline*}
Otherwise $P^{bb}_{g}(n,p)=0$

i have many like this and it eats lot of space.



\end{document}