# PHP Program - Square Root of a Number

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

Alternatively, it can also be expressed as:

x2 = y

### Method 1: 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 = 16;
\$y = 25;

\$x1 = \$x**(1/2);
\$y1 = \$y**(1/2);
echo "Square root of \$x is \$x1 \n";
echo "Square root of \$y is \$y1 \n";
?>
```

The above code will give the following output:

```Square root of 16 is 4
Square root of 25 is 5
```

### Method 2: Using sqrt() function of PHP

The sqrt() function of PHP can be used to return square root of a number.

```<?php
\$x = 16;
\$y = 25;

\$x1 = sqrt(\$x);
\$y1 = sqrt(\$y);
echo "Square root of \$x is \$x1 \n";
echo "Square root of \$y is \$y1 \n";
?>
```

The above code will give the following output:

```Square root of 16 is 4
Square root of 25 is 5
```

### Method 3: Using pow() function of PHP

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

```<?php
\$x = 16;
\$y = 25;

\$x1 = pow(\$x, 0.5);
\$y1 = pow(\$y, 0.5);
echo "Square root of \$x is \$x1 \n";
echo "Square root of \$y is \$y1 \n";
?>
```

The above code will give the following output:

```Square root of 16 is 4
Square root of 25 is 5
```

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