How to make big parenthesis in equation?

Question

I am learning how to make like this, would you mind guys to help me? I just can't make a big parenthesis like this one. Thanks in advance.

Answer 1

for showed example you not need any special parenthesis:

\documentclass{article}
\usepackage{amsmath}

\begin{document}
\[
(f \text{ continuous}) \Leftrightarrow
    \begin{pmatrix}
    \forall f(x) \in X\ \forall V\ni f(x) \\
    \exists U \ni x \text{ such that } f(U)\subset C
    \end{pmatrix}
\]
\end{document}

for more about writing math see wiki/LaTeX/Mathematics, Advanced Mathematics, tutorials/amsmath etc.

Answer 2

use

\documentclass{standalone}
\usepackage{amsmath}

\begin{document}
$
\left(\begin{matrix}
\mbox{first row}\\
\mbox{second row}
\end{matrix}\right)
$
\end{document}

Answer 3

The mathtools package defines an optional argument for the column alignment in its matrix* environments:

\documentclass{article}
\usepackage{mathtools}

\begin{document}

\[
(f \text{ continuous }) \Leftrightarrow
    \begin{pmatrix*}[l]
    \,\forall f(x) \in X\ \forall V\ni f(x) \\
   \, \exists U \ni x \text{ such that } f(U)\subset C
    \end{pmatrix*}
\]

\end{document} 

Answer 4

The construct gathered from amsmath is the main ingredient below with brackets around provided by \left(...\right). Note also correct spacing of quantifiers, as given in https://tex.stackexchange.com/a/115451/15925

\documentclass{article}

\usepackage{amsmath}

\DeclareMathOperator{\Exists}{\exists}
\DeclareMathOperator{\Forall}{\forall}

\begin{document}

\begin{equation*}
  (f\ \text{continuous})
  \iff
  \left(
    \begin{gathered}
      \Forall f(x) \in X \quad \Forall V\ni f(x) \\
      \Exists U \ni x\ \text{such that}\ f(U)\subset C
    \end{gathered}
  \right)
\end{equation*}

\end{document}