Delimiters are parentheses, braces, or other characters used to mark the start and end of subformulas. This formula has three sets of parentheses delimiting the three subformulas.
(zz_0)^2 = (xx_0)^2 + (yy_0)^2
The delimiters do not need to match, so you can enter \( [0,1) \)
.
Here are the common delimiters:
Delimiter  Command  Name 

(  ( 
Left parenthesis 
)  ) 
Right parenthesis 
\} 
{ or \lbrace

Left brace 
\{ 
} or \rbrace

Right brace 
[ 
[ or \lbrack

Left bracket 
] 
] or \rbrack

Right bracket 
⌊  \lfloor 
Left floor bracket 
⌋  \rfloor 
Right floor bracket 
⌈  \lceil 
Left ceiling bracket 
⌉  \rceil 
Right ceiling bracket 
⟨  \langle 
Left angle bracket 
⟩  \rangle 
Right angle bracket 
/  / 
Slash, or forward slash 
\  \backslash 
Reverse slash, or backslash 
 
 or \vert

Vertical bar 
‖ 
\ or \Vert

Double vertical bar 
The mathtools package allows you to create commands for paired delimiters. For instance, if you put \DeclarePairedDelimiter\abs{\lvert}{\rvert}
in your preamble then you get two commands for singleline vertical bars (they only work in math mode). The starred version, such as \abs*{\frac{22}{7}}
, has the height of the vertical bars match the height of the argument. The unstarred version, such as \abs{\frac{22}{7}}
, has the bars fixed at a default height. This version accepts an optional argument, as in \abs[size
command]{\frac{22}{7}}
, where the height of the bars is given in size command, such as \Bigg
. Using \lVert
and \rVert
as the symbols will give you a norm symbol with the same behavior.
• \left & \right  Automatically sized delimiters.  
• \bigl & \bigr etc.  Manually sized delimiters. 
© 2007–2018 Karl Berry
Public Domain Software
http://latexref.xyz/Delimiters.html