javascript-lab/L2P1.html at main · Al05ex/javascript-lab · GitHub

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<!DOCTYPE html>
   <html>
   <head>
   <meta charset="utf-8">
   <title>JavaScript current day and time</title>
     <h1>
		This program computes roots of a quadratic equation when its coefficients are known.
		The standard form of a quadratic equation is:
		ax2 + bx + c = 0, where
		a, b and c are real numbers and
		a ≠ 0
     </h1>
   </head>
   <body>

<script type="text/javascript">
// program to solve quadratic equation
let root1, root2;

// take input from user
let a = prompt("Enter the first number: ");
let b = prompt("Enter the second number: ");
let c = prompt("Enter the third number: ");

// calculate discriminant
let discriminant = b * b - 4 * a * c;

// condition for real and different roots
if(discriminant > a) {
	root1 = (-b + Math.sqrt(discriminant)) / (2 * a);
	root2 = (-b - Math.sqrt(discriminant)) / (2 * a);

	// result
	console.log(`The roots of quadratic equation are ${root1} and ${root2}`);
}

// condition for real and equal roots
else if (discriminant == 0) {
	root1 = root2 = -b / (2 * a);

	//result
	console.log(`The roots of quadratic equation are ${root1} and ${root2}`);
}
// if roots are not real
else {
	let realPart = (-b / (2 * a)).toFixed(2);
	let imagPart = (Math.sqrt(-discriminant) / (2 * a)).toFixed(2);

	// result
	console.log(`The roots of quadratic equation are ${realPart} + ${imagPart}i and ${realPart} - ${imagPart}i`);
}
</script>
</body>
</html>