Synopsis (in math mode or display math mode), one of:
base^exp
base^{exp}
or, one of:
base_exp
base_{exp}
Make exp appear as a superscript of base (with the caret
character, ^) or a subscript (with
underscore, _).
In this example the 0’s and 1’s are subscripts while the
2’s are superscripts.
\( (x_0+x_1)^2 \leq (x_0)^2+(x_1)^2 \)
To have the subscript or superscript contain more than one character,
surround the expression with curly braces, as in e^{-2x}.
This example’s fourth line shows curly braces used to group an expression
for the exponent.
\begin{displaymath}
(3^3)^3=27^3=19\,683
\qquad
3^{(3^3)}=3^{27}=7\,625\,597\,484\,987
\end{displaymath}
LaTeX knows how to handle a superscript on a superscript, or a
subscript on a subscript, or supers on subs, or subs on supers. So,
expressions such as e^{x^2} and x_{i_0} give correct
output. Note the use in those expressions of curly braces to give the
base a determined exp. If you enter \(3^3^3\), this
interpreted as \(3^{3}^{3}\) and then you get TeX error
‘Double superscript’.
LaTeX does the right thing when something has both a subscript and a superscript. In this example the integral has both. They come out in the correct place without any author intervention.
\begin{displaymath}
\int_{x=a}^b f'(x)\,dx = f(b)-f(a)
\end{displaymath}
Note the curly braces around x=a to make the entire expression a
subscript.
To put a superscript or subscript before a symbol, use a construct like
{}_t K^2. The empty curly braces {} give the
subscript something to attach to and keeps it from accidentally
attaching to a prior symbols.
Using the subscript or superscript character outside of math mode or
display math mode, as in the expression x^2, will get you
the TeX error ‘Missing $ inserted’.
A common reason to want subscripts outside of a mathematics mode is to
typeset chemical formulas. There are packages for that, such as
mhchem; see CTAN.