$2^3$

2^3

To write a number in the upper right corner, use "^".

$e^{ i \pi }$

e^{ i \pi }

If you want to write multiple numbers or letters in the upper right corner, put them in braces.

$\exp ( x )$

\exp ( x )

$\sqrt{ 2 }$

\sqrt{ 2 }

\sqrt comes from "square root".

$\sqrt{ \mathstrut a } + \sqrt{ \mathstrut b }$

\sqrt{ \mathstrut a } + \sqrt{ \mathstrut b }

Using \mathstrut, you can align the height of the square root.

$\sqrt[ n ]{ x }$

\sqrt[ n ]{ x }

When writing power roots, use brackets.

$\log x$

\log x

$\log_{ 2 } x$

\log_{ 2 } x

The logarithm base is specified using the "_".

$\ln x$

\ln x