To find the nth root of a number in PHP, we can use the `pow(base, power)`

function, for example the cube root of 27 is equal to 27 raised to the power of 1/3, (\sqrt[3]{27} = 27^{1/3}), since (3^3=27). In general the nth root of x, (\sqrt[n]{x}=x^{1/n}).

To calculate the square root of a number, we can also use the `sqrt(number)`

function.

## Example #

Some example code showing how to calculate roots in PHP is below:

<?php // Square root echo sqrt(49) . "<br />"; // square root of 49 echo pow(49,1/2) . "<br />"; // alternative to square root of 49 echo pow(8,1/2). "<br />"; // square root of 8 // cube root echo pow(8,1/3). "<br />"; // cube root of 8 echo pow(27,1/3). "<br />"; // cube root of 27 // higher roots echo pow(390625,1/4). "<br />"; echo "25^4 = " . pow(25,4) . "<br />"; echo pow(1234, 1/6). "<br />"; ?>

The output from this example is as follows:

7 7 2.8284271247462 2 3 25 25^4 = 390625 3.2750594908837

You can also use the `pow()`

function in PHP to raise one number to the power of another (i.e. take the exponent). We cover this in a separate guide: Raise a Number to the Power of Another in PHP.