Approximating a square root
<HTML> <HEAD> <TITLE>Approximating a square root</TITLE> </HEAD> <BODY> <?php $target = 81; $guess = 1.0; $precision = 0.0000001; $guess_squared = $guess * $guess; while (($guess_squared - $target > $precision) or ($guess_squared - $target < - $precision)) { print("Current guess: $guess is the square root of $target<BR>"); $guess = ($guess + ($target / $guess)) / 2; $guess_squared = $guess * $guess; } print("$guess squared = $guess_squared<BR>"); ?> </BODY> </HTML>