1

In the following situation, I want to vertical align the equal signs = in labeled (H) and (NH) equations (so they can be referenced later using \eqref) at not-consecutive lines. How could I do it?

The way in here does not work for using \eqred later.

enter image description here

\documentclass[12pt]{article}
\usepackage{amsmath,amsthm,amssymb}
\begin{document}
Consider the {\itshape homogeneous} linear differential equation
\begin{equation}
    \tag{H}
    \label{eq:H2}
    y''+p(x)y'+q(x)y=0
\end{equation}
and {\itshape nonhomogeneous} linear differential equation
\begin{equation}
    \tag{NH}
    \label{eq:NH2}
    y''+p(x)y'+q(x)y=f(x)
\end{equation}
where $p(\cdot)$, $q(\cdot)$, and $f(\cdot)$ be continuous functions on some open interval $(a,b)$. The homogeneous equation \eqref{eq:H2} always have a solution $y=0$ called {\itshape the trivial solution}.
\end{document}
Black Mild
  • 17,569
  • Follow Campa's answer \intertext, I found an involving link https://tex.stackexchange.com/questions/49537/putting-equations-in-intertext-to-annotate-a-proof – Black Mild Oct 07 '20 at 10:48

1 Answers1

3

Use align with \intertext (both features of amsmath)

\documentclass[12pt]{article}
\usepackage{amsmath,amsthm,amssymb}
\begin{document}
Consider the \textit{homogeneous} linear differential equation
\begin{align}
    \tag{H}
    \label{eq:H2}
    y''+p(x)y'+q(x)y &= 0
\intertext{and \textit{nonhomogeneous} linear differential equation}
    \tag{NH}
    \label{eq:NH2}
    y''+p(x)y'+q(x)y &= f(x)
\end{align}
where $p(\cdot)$, $q(\cdot)$, and $f(\cdot)$ be continuous functions on some
open interval $(a,b)$. The homogeneous equation \eqref{eq:H2} always have a
solution $y=0$ called \textit{the trivial solution}.
\end{document}

enter image description here

(I replaced {\itshape...} by \textit{...} but that's just my taste.)

campa
  • 31,130