Javascript Program to Solve Quadratic Equations

In this article, we will see a JavaScript program to Solve Quadratic Equations and for this purpose, we must know what is Quadratic Equation.

Standard form of the quadratic equation :

ax2+bx+c = 0,
a β‰  0

Here a, b and c are coefficient (real number) which is entered by the user. Point to remember that value of ‘a’ can not be zero.

Formula to find the root of the equation :

Every quadratic equation has two roots. Let, these roots are x and y. Then the formula is:

(x,y) = (-b ± √b2-4ac)/2

The nature of a root depends upon the discriminant of a quadratic equation i.e. b2-4ac. b2-4ac is knowns as the discriminant of a quadratic equation.

  1. If the discriminant is greater than 0, the roots are real and different.
  2. If the discriminant is equal to 0, the roots are real and equal.
  3. If the discriminant is less than 0, the roots are complex and different.

Let’s see a Javascript Program to Solve Quadratic equations.

<html>
    <head>
        <title>Quadratic Equation</title>
    </head>
    <body>
        <h1>Javascript Program to Solve Quadratic Equation</h1>
        <h2>Quadratic Equation is : ax<sup>2</sup>+bx+c</h2>
        <input type = "button" value="Find Root" onclick="func()">
        <script>
            function func() {
            let a = prompt("Enter the value of a");
            let b = prompt("Enter the value of b");
            let c = prompt("Enter the value of c");
            let discriminant = b*b - 4*a*c;
            //(-b ± √b2-4ac)/2
            let x = (-b+ Math.sqrt(discriminant))/2;
            let y = (-b- Math.sqrt(discriminant))/2;
            alert("Your first root is"+x);
            alert("your second root is"+y); 
            }
      
        </script>
    </body>
</html>

Output :