<?php
#The sqrt function finds the square root of a number
echo(sqrt(4));
# Outputs 2
echo(sqrt(-4));
#This is an impossible maths equation so, it returns NaN
?><?php
echo(sqrt(0) . "<br>");
echo(sqrt(1) . "<br>");
echo(sqrt(9) . "<br>");
echo(sqrt(0.64) . "<br>");
echo(sqrt(-9));
?><?php
/*
The sqrt() function returns square root of a positive float number.
Since square root for negative number is not defined, it returns NAN.
This is one of the most commonly used functions. This function always
returns a floating point number. Eg:
*/
echo(sqrt(0) . "<br>"); // output: 0
echo(sqrt(1) . "<br>"); // output: 1
echo(sqrt(9) . "<br>"); // output: 3
echo(sqrt(0.64) . "<br>"); // output: 0.8
echo(sqrt(-9)); // output: NAN
// I hope this helps!
?>