## Custom expression

Some things you can do when selecting "Custom expression":

`x`

: the variable
`x + 1`

, `x - 1`

, `x * 2`

, `x / 2`

: addition, subtraction, multiplication, division, respectively. Respects order of operations.
`sin(x)`

, `cos(x)`

, `tan(x)`

: trig functions
`asin(x)`

etc.: inverse trig functions
`sqrt(x)`

: square root
`PI`

, `E`

: constants
`pow(x, 2)`

: raise `x` to the second power

All of this is case-sensitive.