[Tex/LaTex] Equation numbering not shown

equationslabels

I am writing an equation using the syntax s follows:-

{
\[
  N\!D_{\max} = 
   \begin{cases}
    \frac{n}{2} &:  \text{$n$   even,} \\ 
    \frac{n-1}{2} &: \text{$n$  odd.}
   \end{cases}
\]  }\label{form:19}

I am able to label the equation during a sentence but the same equation number is not being shown beside the equation. How can I fix this problem? A picture

enter image description here

is attached for better understanding.

Best Answer

You can use equation environment to get equation numbers or you can use \tag statement to give whatever equation number that you want to give.

enter image description here

{
\[
  N\!D_{\max} = 
   \begin{cases}
    \frac{n}{2} &:  \text{$n$   even,} \\ 
    \frac{n-1}{2} &: \text{$n$  odd.}
   \end{cases}
\]  }\label{form:19}

Referring to Equation~\ref{form:19}.


{
\[
  N\!D_{\max} = 
   \begin{cases}
    \frac{n}{2} &:  \text{$n$   even,} \\ 
    \frac{n-1}{2} &: \text{$n$  odd.}
   \end{cases}\tag{3.2}\label{form:19a}
\]  }

Referring to Equation~\ref{form:19a}.


\begin{equation}
  N\!D_{\max} = 
   \begin{cases}
    \frac{n}{2} &:  \text{$n$   even,} \\ 
    \frac{n-1}{2} &: \text{$n$  odd.}
   \end{cases}
   \label{form:19b}
\end{equation}

Referring to Equation~\ref{form:19b}.
Related Question