# LaTeX multiline equation is not working!

Hi all,

I am using LeD and texlive09 for latex editing. I want to render a multi-line equation and for that I am trying with "\\" - this operator. But it is not rendering. I have included "amsmath" package. I am clueless about why the problem happens. Please help me...

Regards
Sam

What are you trying to type? You can even just enter it into your reply to test if it works. Quote my reply to see what I typed below:

$$\begin{gather*} \nabla \cdot \vec E = \frac{\rho}{\epsilon_0} \\ \nabla \times \vec E = -\dfrac{\partial \vec B}{\partial t} \\ \nabla \cdot \vec B = 0 \\ \nabla \times \vec B = \mu_0\epsilon_0\dfrac{\partial \vec E}{\partial t} + \mu_0 \vec J \end{gather*}$$

Yes it works! But it doesn't show up the reference to the equation in toc. using \begin{equation} it should work...shouldn't it?

regards
Sam

minger
You typically have to enter an additional environment. I don't believe the standard compiler I use allows multiline equations simply inside of the equation environment. I use the split environment, e.g.
$$\begin{equation} \begin{split} a &= b + 1\\ c &= a + 10 \end{split} \end{equation}$$

Code:
\begin{equation}
\begin{split}
a &= b + 1\\
c &= a + 10
\end{split}
\end{equation}

Hepth
Gold Member
I always use "\begin{eqnarray}" then your \\ will work., though it numbers the lines.

If the problem persists it may be you're trying to break up brackets:

Code:
\begin{equation}
\begin{array}{c}
this is a test \left(hello \\
hello two \right)
\end{array}
\end{equation}

gives an error but

Code:
\begin{equation}
\begin{array}{c}
this is a test (hello \\
hello two )
\end{array}
\end{equation}

doesn't. Can't split the \left( and \right)'s up

Last edited:
I always use "\begin{eqnarray}" then your \\ will work., though it numbers the lines.

If the problem persists it may be you're trying to break up brackets:

Code:
\begin{equation}
\begin{array}{c}
this is a test \left(hello \\
hello two \right)
\end{array}
\end{equation}

gives an error but

Code:
\begin{equation}
\begin{array}{c}
this is a test (hello \\
hello two )
\end{array}
\end{equation}

doesn't. Can't split the \left( and \right)'s up

You cannot split \left<stuff> and \right<stuff>
You must use "fake" right/left instead:

Code:
\begin{equation}
\begin{array}{c}
this is a test \left(hello \right.\\
\left. hello two \right)
\end{array}
\end{equation}

There are several environments that essentially perform the same thing with subtle differences.

I personally use {align} if I want to reference every line.

hi!!

I have this equation that I want to split in 4 parts.

$d(x,z) = \mid x-z \mid _{p} = \mid (x-y) + (y-z) \mid _{p} \leqslant \mbox{ max (} \mid x-y \mid _{p} \mbox{, } \mid y-z \mid _{p} \mbox{)} = \mbox{ max (} d(x,y), d(y,z) \mbox{).}$

I have tried : $d(x,z) = & \left(\mid x-z \mid _{p} \right. \\ & \left. = \mid (x-y) + (y-z) \mid _{p} \right. \\ & \left. \leqslant \mbox{ max (} \mid x-y \mid _{p} \mbox{, } \mid y-z \mid _{p} \mbox{)} \right. \\ & \left. \mbox{ max (} d(x,y), d(y,z) \mbox{).}$ \right) \]

But it is not working.

Can you help me? Thank you,
Miha

\begin{align} d(x,z) &= \mid x-z \mid _{p} \\ &= \mid (x-y) + (y-z) \mid _{p} \\ &\leqslant \mbox{ max (} \mid x-y \mid _{p} \mbox{, } \mid y-z \mid _{p} \mbox{)} \\ &= \mbox{ max (} d(x,y), d(y,z) \mbox{).} \end{align}

If you don't want equation numbers, use the starred versions of align,
\begin{align*} d(x,z) &= \mid x-z \mid _{p} \\ &= \mid (x-y) + (y-z) \mid _{p} \\ &\leqslant \mbox{ max (} \mid x-y \mid _{p} \mbox{, } \mid y-z \mid _{p} \mbox{)} \\ &= \mbox{ max (} d(x,y), d(y,z) \mbox{).} \end{align*}

Thank you very much!!

regards,
miha