顶部对齐嵌套数学环境

Question

我怎样才能让它出现在与没有包的环境y_* =第一行相同的级别上？aligneddelarray

\documentclass{article}
\usepackage{mathtools}

\DeclareMathOperator{\const}{\mathop{C}}

\begin{document}

\begin{align}
y_* &=
    \begin{aligned}
        \const_{10}e^{\lambda_1 x}+\const_{11}xe^{\lambda_1 x}+\const_{12}x^2e^{\lambda_1 x}&\\
        +&\const_{20}e^{\lambda_2 x} \>=
    \end{aligned}
    \\[2ex]
&=
    \begin{aligned}
        1+x+x^2&\\
        +&e^{-x}
    \end{aligned}
\end{align}

\end{document}

Answer 1

您可以使用环境t中的选项aligned。

\documentclass{article}
\usepackage{mathtools}

\DeclareMathOperator{\const}{\mathop{C}}

\begin{document}

\begin{align}
y_* &=
    \begin{aligned}[t]
        \const_{10}e^{\lambda_1 x}+\const_{11}xe^{\lambda_1 x}+\const_{12}x^2e^{\lambda_1 x}&\\
        +&\const_{20}e^{\lambda_2 x} \>=
    \end{aligned}
    \\[2ex]
&=
    \begin{aligned}[t]
        1+x+x^2&\\
        +&e^{-x}
    \end{aligned}
\end{align}

\end{document}