Text and matrix side by side

Question

\begin{center}
        \[
        $$  [\textbf{u}]=
         \begin{bmatrix}
             u_1  \\
             u_2  \\
             u_3
        \end{bmatrix}$$
        $\in$ $\mathbb{M}_{3\times1}$ 
        \]

    \end{center}

I used the above code to print my matrix and text side by side. I am getting the error bad math delimitor. Suggest an alternative for this issue.

Answer 1

The correct form most likely is:

\[    % <--- start of math mode
[\mathbf{u}]=
 \begin{bmatrix}
     u_1  \\
     u_2  \\
     u_3
\end{bmatrix}
    ,\quad \in\mathbb{M}_{3\times 1}
\]    % <--- end of math mode

Note: you made the same mistake as can be seen in Missing $ inserted for matrices. beside this, the use of $$ in latex document is deprecated. instead it use \[ ... \].

Also \mathbf{u} is the right command rather than \textbf{u}.