# cbrt()

Returns the cube root of a double value.

## Syntax

`Numeric cbrt()`

## Usage

For positive finite `x`, cbrt(-`x`) ==
-cbrt(`x`); that is, the cube root of a negative value is the negative of the cube
root of that value's magnitude.

Special cases:

- If the value is NaN, then the result is NaN.
- If the value is infinite, then the result is an infinity with the same sign as the value.
- If the value is zero, then the result is a zero with the same sign as the value.

The computed result must be within 1 ulp of the exact result.