For some reason, when a=1, b=1, c=-1, I am not getting the desired result of -1.6180339887499 and 0.61803398874989. Instead, I get 2 and 1. What am I doing wrong?
function solve(a,b,c){
var result = (((-1*b) + Math.sqrt(Math.pow(b,2)) - (4*a*c))/(2*a));
var result2 = (((-1*b) - Math.sqrt(Math.pow(b,2)) - (4*a*c))/(2*a));
return result + "<br>" + result2;
}
document.write( solve(1,1,-1) );For some reason, when a=1, b=1, c=-1, I am not getting the desired result of -1.6180339887499 and 0.61803398874989. Instead, I get 2 and 1. What am I doing wrong?
function solve(a,b,c){
var result = (((-1*b) + Math.sqrt(Math.pow(b,2)) - (4*a*c))/(2*a));
var result2 = (((-1*b) - Math.sqrt(Math.pow(b,2)) - (4*a*c))/(2*a));
return result + "<br>" + result2;
}
document.write( solve(1,1,-1) );4 Answers
Reset to default 9You need another grouping:
var result = (((-1 * b) + Math.sqrt(Math.pow(b, 2)) - (4 * a * c)) / (2 * a)); // wrong
var result2 = (((-1 * b) - Math.sqrt(Math.pow(b, 2)) - (4 * a * c)) / (2 * a)); // wrong
vs
var result = (-1 * b + Math.sqrt(Math.pow(b, 2) - (4 * a * c))) / (2 * a); // right
var result2 = (-1 * b - Math.sqrt(Math.pow(b, 2) - (4 * a * c))) / (2 * a); // right
All together:
function solve(a, b, c) {
var result = (-1 * b + Math.sqrt(Math.pow(b, 2) - (4 * a * c))) / (2 * a);
var result2 = (-1 * b - Math.sqrt(Math.pow(b, 2) - (4 * a * c))) / (2 * a);
return result + "<br>" + result2;
}
document.write(solve(1, 1, -1));Try
var a, b, c, discriminant, root1, root2, r_Part, imag_Part;
document.write(realpart ="+r_Part" and imaganary part ="+imag_Part");
discriminant = b*b-4*a*c;
if (discriminant > 0)
{
root1 = (-b+sqrt(discriminant))/(2*a);
root2 = (-b-sqrt(discriminant))/(2*a);
document.write(real part ="+r_Part" and imaganary part ="+imag_Part");
}
else if (discriminant == 0)
{
root1 = root2 = -b/(2*a);
document.write(real part ="+r_Part" and imaganary part ="+imag_Part");
}
else
{
r_Part = -b/(2*a);
imag_Part = sqrt(-discriminant)/(2*a);
document.write(real part ="+r_Part" and imaganary part ="+imag_Part");
}
function solve(a, b, c) {
var result = ((-1 * b + Math.sqrt(Math.pow(b, 2) - (4 * a * c))) / (2 * a)).toFixed(3);
var result2 = ((-1 * b - Math.sqrt(Math.pow(b, 2) - (4 * a * c))) / (2 * a)).toFixed(3);
return "{"+result + "," + result2+"}";
}
document.write(solve(1, -4, -7));
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<title></title>
<link rel="stylesheet" href="">
</head>
<body>
<script type="text/javascript">
var a=2;
var b=9;
var c=2;
var root_part=Math.sqrt(b*b-4*a*c);
var denom=2*a;
if (isNaN(root_part) === true){
document.write("<br> Impossible to solve");
}
else{
var root1=(-b+root_part)/denom;
var root2=(-b-root_part)/denom;
document.write("<br>First Root is="+root1+ " and Second Root is="+root2);
}
</script>
</body>
</html>