Added QuadraticRoots to Math/QuadraticRoots.js

Maths/QuadraticRoots.js

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+/**
+ * @see https://www.cuemath.com/algebra/roots-of-quadratic-equation/
+ * @author Dibya Debayan Dash
+ * Calculates the roots of a quadratic equation of the form ax^2 + bx + c = 0.
+ *
+ * @param {number} a - Coefficient of x^2.
+ * @param {number} b - Coefficient of x.
+ * @param {number} c - Constant term.
+ * @returns {number[]|string} - An array containing the roots if they are real,
+ * or a string indicating no real roots.
+ *
+ * @example
+ * // Find the roots of the quadratic equation: 2x^2 - 4x + 2 = 0
+ * const roots = quadraticRoots(2, -4, 2);
+ * // Expected output: [1, 1]
+ */
+const quadraticRoots = (a, b, c) => {
+ // Calculate the discriminant
+ const discriminant = b * b - 4 * a * c
+
+ // Check if roots are real
+ if (discriminant < 0) {
+ return 'No real roots'
+ } else if (discriminant === 0) {
+ // One real root
+ return [-b / (2 * a)]
+ } else {
+ // Two real roots
+ const sqrtDiscriminant = Math.sqrt(discriminant)
+ return [
+ (-b + sqrtDiscriminant) / (2 * a),
+ (-b - sqrtDiscriminant) / (2 * a)
+ ]
+ }
+}
+
+export { quadraticRoots }

Maths/test/QuadraticRoots.test.js

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+import { quadraticRoots } from '../QuadraticRoots.js'
+
+// Test case 1: Two real roots
+test('returns an array with two real roots when the discriminant is positive', () => {
+ expect(quadraticRoots(1, -3, 2)).toEqual([2, 1])
+})
+
+// Test case 2: One real root
+test('returns an array with one real root when the discriminant is zero', () => {
+ expect(quadraticRoots(1, -2, 1)).toEqual([1])
+})
+
+// Test case 3: No real roots
+test('returns a message indicating no real roots when the discriminant is negative', () => {
+ expect(quadraticRoots(1, 2, 5)).toEqual('No real roots')
+})