UNSW ProgComp: Problem 2 - 2007

<?php

function number_fits_criterion($a){
    $p = abs(pow($a, 2) - $a - 1);
    if(abs(pow($a, 2) - $a - 1) < pow(10, -14)){
        echo "p^2 - p - 1: $p\n";
        return false;
    }else{
        return true;
    }
}

$x = 1;
$y = 1;
$a = 1;

while(number_fits_criterion($a)){
    //find next fib
    $temp = $y;
    $y = $y + $x;
    $x = $temp;
    $a = $y/$x;
}
echo "p: $a\n";
echo "Fibonacci Numbers: $x, $y \n";