Sample Calculator with Plotting

by Ron Eaglin

HTML

Quadratic Equation Calculator<br/><br>
y = ax<sup>2</sup> + bx + c<br/><br/>

     Input a <input type="text" id="a" /><br/>
     Input b <input type="text" id="b" /><br/>
     Input c <input type="text" id="c" /><br/>
     X min<input type="text" id="xmin" />
     X max<input type="text" id="xmax" /><br/><br/>
    
<input type="button" value="Update" />
<br/><br/>
<p id="output"> </p>

JavaScript

function calculateY(a, b, c, x) {
    return a * x * x + b * x + c;
}

function calculate() {
    var a = Number($('#a').val());
    var b = Number($('#b').val());
    var c = Number($('#c').val());
    var xmin = Number($('#xmin').val());
    var xmax = Number($('#xmax').val());
    var x = 0;
    var y = 0;
    
    var s = "";
    
    for (x = xmin; x <= xmax; x++) {
        y = calculateY(a, b, c, x);
        s += " X = " + x + " Y = " + y + "<br/>";
    }
    output.innerHTML = s;
}

$('input[type=button]').click( function() {
     calculate();  
});