答案1
它可以通过大量的视觉格式来完成,但我更喜欢我提出的第二种方法,在我看来,这种方法足够清晰。
\documentclass{article}
\usepackage{amsmath}
\DeclareMathOperator{\RE}{Re}
\DeclareMathOperator{\IM}{Im}
\begin{document}
\begin{equation*}
\begin{bmatrix}
\dfrac{\partial^2 F}{\partial^2\RE{a}} \\[3ex]
\dfrac{\partial^2 F}{\partial^2\IM{a}} \\[3ex]
\begin{matrix}
\dfrac{\partial^2 F}{\partial^2 b_1} \\[3ex]
\dfrac{\partial^2 F}{\partial^2 b_2}
\end{matrix}
\rlap{%
\quad
$\displaystyle
\left.
\vphantom{%
\begin{matrix}
\dfrac{\partial^2 F}{\partial^2 b_1} \\[3ex]
\dfrac{\partial^2 F}{\partial^2 b_2}
\end{matrix}%
}\right\rbrace
\dfrac{\partial^2 F}{\partial^2 \mathbf{b}}
$\quad where $\mathbf{b}=\begin{bmatrix} b_1 & b_2 \end{bmatrix}$%
}
\end{bmatrix}
\hphantom{%
\displaystyle
\left.
\vphantom{%
\begin{matrix}
\dfrac{\partial^2 F}{\partial^2 b_1} \\[3ex]
\dfrac{\partial^2 F}{\partial^2 b_2}
\end{matrix}%
}\right\rbrace
\dfrac{\partial^2 F}{\partial^2 \mathbf{b}}
\text{\quad where $\mathbf{b}=\begin{bmatrix} b_1 & b_2 \end{bmatrix}$}%
}
\end{equation*}
\begin{equation*}
\begin{bmatrix}
\dfrac{\partial^2 F}{\partial^2\RE{a}} \\[3ex]
\dfrac{\partial^2 F}{\partial^2\IM{a}} \\[3ex]
\dfrac{\partial^2 F}{\partial^2 b_1} \\[3ex]
\dfrac{\partial^2 F}{\partial^2 b_2}
\end{bmatrix}
=
\begin{bmatrix}
\dfrac{\partial^2 F}{\partial^2\RE{a}} \\[3ex]
\dfrac{\partial^2 F}{\partial^2\IM{a}} \\[3ex]
\dfrac{\partial^2 F}{\partial^2 \mathbf{b}}
\end{bmatrix}
\qquad
\text{where $\mathbf{b}=\begin{bmatrix} b_1 & b_2 \end{bmatrix}$}
\end{equation*}
\end{document}
答案2
也许这个bigdelim
包可以有所帮助:
\documentclass{article}
\usepackage{amsmath}
\usepackage{bigdelim}
\begin{document}
\[
\begin{array}{c}
\ldelim[{4}{*} a \rdelim]{4}{*}\\
b\\
c\\
d
\end{array}
\hspace*{-0.4cm}
\begin{array}{l}
\\
\\
\rdelim\}{2}{*}[$\Rightarrow \frac{\partial^2 F}{\partial^2 b} \quad \text{ where } b=...$]\\
\\
\end{array}
\]
\end{document}