sqrt

Square root

&reftitle.description; `float` `sqrt` `float` `num`

Returns the square root of `num`.

&reftitle.parameters;

`num`

- The argument to process

&reftitle.returnvalues;

The square root of `num` or the special value `NAN` for negative numbers.

&reftitle.examples;

### `sqrt` example

    <?php
    // Precision depends on your precision directive
    echo sqrt(9); // 3
    echo sqrt(10); // 3.16227766 ...
    ?>

&reftitle.seealso;

- `pow`
- `M_SQRTPI` - `sqrt(pi)`
- `M_2_SQRTPI` - `2/sqrt(pi)`
- `M_SQRT2` - `sqrt(2)`
- `M_SQRT3` - `sqrt(3)`
- `M_SQRT1_2` - `1/sqrt(2)`