Quadratic Equations are of the form ax2 + bx + c = 0. To find roots(root1 and root2) of such an equation, we need to use the formula
Video Explaining The JavaScript Code To Find Roots of a Quadratic Equation:
[youtube https://www.youtube.com/watch?v=Td6QViKdbZU]
To calculate the roots of a quadratic equation using a computer program, we need to break down the formula and calculate smaller parts of it and then combine to get the actual solution.
So lets calculate square root of b2 – 4 * a * c and store it in variable root_part. Also store 2 * a in variable denom. Now calculate ( – b + root_part ) / denom and store it in root1 and ( – b – root_part ) / denom in root2.
Output the values of root1 and root2 to the browser using document.write statement.
Javascript Coding Explained In Above Video:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 | <title>Quadratic Equation</title> <script type="text/javascript"> <!-- var a = prompt("Enter value of a","1"); var b = prompt("Enter value of b","4"); var c = prompt("Enter value of c","4"); var root_part = Math.sqrt(b * b - 4 * a * c); var denom = 2 * a; var root1 = ( -b + root_part ) / denom; var root2 = ( -b - root_part ) / denom; document.write("1st root: "+root1+"<br />"); document.write("2nd root: "+root2+"<br />"); // --> </script> |
Usually people will make mistake in this line
var root_part = Math.sqrt(b * b - 4 * a * c); |
Be sure that, you write capital letter M in Math.sqrt.
Work Space:
Quadratic Equation: ax2 + bx + c = 0
Let,
a = 1
b = 4
c = 4
i.e., 1x2 + 4x + 4 =0
=> 1x2 + 2x + 2x + 4 = 0
=> x ( x + 2 ) + 2 ( x + 2 ) = 0
=> ( x + 2 ) + ( x + 2 ) = 0
=> x + 2 = 0 AND x + 2 = 0
=> x = -2 AND x = -2