How to represent PHI formula in PHP

Question

I'm trying to use this formula in PHP code, But I can't find a way to represent it.

phi = (A+B)/A = A/B

Say I have a number:

$a = 275;

I want the value of $b to be in the golden ratio with relation to $a; I know I can find the PHI constant by:

$phi = (1+sqrt(5))/2; 

I don't know how to apply it.

Answer 1

as you have mentioned in your question, the formula of phi is (a+b)/a = a/b and you have the value of the phi from (1+sqrt(5))/2

if you have the value of a , then you can find the value of b derived from phi = a/b to be b = phi/a

in PHP that would be

define('PHI', (1+sqrt(5))/2);

function goldenRatio($num){
    return PHI/$num;
}

var_dump(goldenRatio(1)); // returns 0.618033989
var_dump(goldenRatio(2)); // returns 1.236067977
var_dump(goldenRatio(3)); // returns 1.854101966