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Putting (\ref{7.1}) and (\ref{eq9}) in (\ref{6}), we get \ref{eq8}

This prints as

Putting (7.1) and (3) in (3), we get 3

where eq6, eq8 and eq9 are labeled inline, 7.1 is labeled inside \begin{align)

$$Y = C_3 \cos ky + C_4 \sin ky \eqno{(9)} \label{eq9}$$     
\begin{align}
    \frac{\mathrm{d}^2 X}{\mathrm{d}^2 x^2} - k^2X = 0 \tag{7.1} \label{7.1}
\end{align}

so the inline labels aren't working. How to fix this?

Qrrbrbirlbel
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P4Penguin
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    Using $$ $$ does not give you an equation number. Use the equation environment instead. Besides, you can use \eqref{} macro which includes the bracket for you. By the way, use \[ \] or equation* environment instead of $$ $$. – Teddy van Jerry Nov 21 '22 at 05:31
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    Unrelated but using numbers in your labels (like eq9) is not really how labels are intended to be used, the idea is that you use a descriptive name in your label and let LaTeX handle everything related to numbering automatically. So use for example \label{pythagoreantheorem} instead of \label{eq9}. – Marijn Nov 21 '22 at 08:00
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    $$ isn't inline-math. Don't use $$: Why is \[ … \] preferable to $$? – Qrrbrbirlbel Nov 25 '22 at 10:20
  • Welcome to TeX:SE! From your code fragments not possible to see, what you intend to do. Please, extend them to complete small document with your equations. BTW, inline math terms, i.e. math terms in text, cannot be numbered. – Zarko Nov 25 '22 at 11:29

0 Answers0