# PHP Program - Cube Root of a Number

If a number is multiplied by itself two times (*n*n*n*), the final number will be the cube of that number and finding the **cube root** of a number is inverse operation of cubing the number. If *x* is the cube root of *y*, it can be expressed as below:

Alternatively, it can also be expressed as:

*x ^{3} = y*

### Example: Using exponent operator of PHP

The exponential (**) operator of PHP can be used to calculate the cube root of a number. Consider the following example.

<?php $x = 64; $y = 125; $x1 = $x**(1/3); $y1 = $y**(1/3); echo "Cube root of $x is $x1.\n"; echo "Cube root of $y is $y1.\n"; ?>

The above code will give the following output:

Cube root of 64 is 4. Cube root of 125 is 5.

### Example: Using pow() function of PHP

The pow() function of PHP can also be used to calculate cube root of a number.

<?php $x = 64; $y = 125; $x1 = pow($x, 1/3); $y1 = pow($y, 1/3); echo "Cube root of $x is $x1.\n"; echo "Cube root of $y is $y1.\n"; ?>

The above code will give the following output:

Cube root of 64 is 4. Cube root of 125 is 5.