The **`sqrt()` function** in Perl returns the *square root* of a non-negative number. 

Figure 1 below shows the mathematical representation of the `sqrt()` function.

# 
#  Syntax
---
```perl
sqrt(number)
```
---

# 
## Parameter

`sqrt()` requires a non-negative number as a parameter. If the number is negative, an `Error` will be thrown.

##
## Return value

`sqrt()` returns the square root of the number sent as a parameter.

# 
## Code

The following example shows how to use `sqrt()` function in Perl.

print "sqrt(4): " .sqrt(4). "\n";

print "sqrt(0): " .sqrt(0). "\n";

print "sqrt(25): " .sqrt(25). "\n";

print "sqrt(4.5): " .sqrt(4.5). "\n";

What is sqrt() in Perl?

The Perl `sqrt()` function returns the square root of a non-negative number; errors on negative.