Solve Quadratic Equations with the Formula

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1

This is a function I wrote a while ago to save me the time of pounding it into a calculator over and over again during a Maths homework.

//////////////////////////////////////////
////// Function to solve quadratics //////
//////       by the eqaution:       //////
//////                              //////
//////      -b ± sqrt(b² - 4ac)     //////
//////       ————————————————       //////
//////              2a              //////
//////                              //////
////// By Sam Kellett               //////
////// ([http://cannedlaughter.net](http://cannedlaughter.net))  //////

function quadratic(a,b,c) {
    step1a = -b + Math.sqrt((b*b) - (4 * a * c));
    trace("step 1a: "+step1a);
    step2a = step1a/(2*a);
    trace("step 2a: "+step2a);
    
    step1b = -b - Math.sqrt((b*b) - 4 * a * c);
    trace("step 1b: "+step1b);
    step2b = step1b/(2*a);
    trace("step 2b: "+step2b);
    
    var x:Array = new Array(step2a,step2b);
    return x;
}

// if you had x² - 3x - 4
// We take a, b & c from ax² + bx + cx
// so a = 1, b = -3 and c = -4 
// you would call the function like so:
example = quadratic(1,-3,-4);

// the variable example will now be an array 
// containing the two possible answers produced 
// by the formula
trace(example);
// returns:
// "4,-1"