Worksheet on Nature of the Roots of a Quadratic Equation

Practice the questions given in the Worksheet on nature of the roots of a quadratic equation.

We know the nature of the roots of a quadratic equation depends completely on the value of its discriminant.

1. Without solving, comment upon the nature of roots of each of the following equations:

(a) 7x\(^{2}\) - 9x + 2 = 0

(b) 6x\(^{2}\) - 13x + 4 = 0

(c) 25x\(^{2}\) - 10x + 1 = 0

(d) x\(^{2}\) + 2√3 x - 9 = 0

(e) x\(^{2}\) - ax + b\(^{2}\) = 0

(f) 2x\(^{2}\) + 8x + 9 = 0

2. Find the discriminant of the following equations.

(a) x(x - 2) + 1 = 0

(b) \(\frac{1}{x + 2}\) + \(\frac{1}{x - 2}\) = 2

3. Prove that none of the following equations has any real solution.

(a) x\(^{2}\) + x + 1 = 0

(b) x(x - 1) + 1 = 0

(c) x + \(\frac{4}{x}\) - 1 = 0, x ≠ 0

(d) x(x + 1) + 3(x + 3) = 0

(e) \(\frac{x}{x + 1}\) + \(\frac{3}{x - 1}\) = 0; x ≠ 1, -1

4. Find the value of ‘p’, if the following quadratic equation has equal roots: 4x\(^{2}\) - (p - 2)x + 1 = 0

5. Prove that each of the following equation has only one solution. Find the solution.

(a) 4y\(^{2}\) - 28y + 49 = 0

(b) \(\frac{1}{4}\)x\(^{2}\) + \(\frac{1}{3}\)x + \(\frac{1}{9}\) = 0

(c) 8x(2x - 5) + 25 = 0

6. Find the value of λ for which the equation λx\(^{2}\) + 2x + 1 = 0 has real and distinct roots.

7. For what value of k will each of the following equations give equal roots? Also, find the solution for that value of k.

(a) 3x\(^{2}\) + kx + 2 = 0

(b) kx\(^{2}\) - 4x + 1 = 0

(c) 5x\(^{2}\) + 20x + k = 0

(d) (k - 12)x\(^{2}\) + 2(k - 12)x + 2 = 0

8. The equation 3x\(^{2}\) - 12x + z - 5 = 0 has equal roots. Find the value of z.

9. Find k for which the equation 4x\(^{2}\) + kx + 9 = 0 will be satisfied by only one real value of x. Also find the solution.

10. Find the value of ‘z’, if the following equation has equal roots:

(z - 2)x\(^{2}\) - (5 + z)x + 16 = 0

11. Find the nature of roots of the following equation. If they are real, find them.

(a) 3x\(^{2}\) - 2x + \(\frac{1}{3}\) = 0

(b) 3x\(^{2}\) - 6x + 2 = 0

Answers for the Worksheet on nature of the roots of a quadratic equation are given below.

Answers:

1. (a) Rational and unequal

(b) Irrational and unequal

(c) Rational (real) and equal

(d) Irrational and unequal (since, b = 2√3 is irrational)

(e) Irrational and unequal

(f) Imaginary roots

2. (a) 0

(b) 17

4. p = -2 or 6

5. (a) \(\frac{7}{2}\)

(b) -\(\frac{2}{3}\)

(c) \(\frac{5}{4}\)

6. All real values of λ < 1.

7. (a) ±2√6; when k = 2√6, solution = -\(\frac{2}{√6}\) and when k = -2√6, solution = \(\frac{2}{√6}\)

(b) 4; solution = -\(\frac{1}{2}\)

(c) 20; solution = -2

(d) 14; solution = -1

8. z = 17

9. ± 12; when k = 12, solution = -\(\frac{3}{2}\) and when k = -12, solution = \(\frac{3}{2}\)

10. z = 3 or 51

11. (a) Real, Roots = \(\frac{1}{3}\), \(\frac{1}{3}\)

(b) Real, Roots = \(\frac{√3 - 1}{√3}\), \(\frac{√3 + 1}{√3}\)

Quadratic Equation

Introduction to Quadratic Equation

Formation of Quadratic Equation in One Variable

Solving Quadratic Equations

General Properties of Quadratic Equation

Methods of Solving Quadratic Equations

Roots of a Quadratic Equation

Examine the Roots of a Quadratic Equation

Problems on Quadratic Equations

Quadratic Equations by Factoring

Word Problems Using Quadratic Formula

Examples on Quadratic Equations 

Word Problems on Quadratic Equations by Factoring

Worksheet on Formation of Quadratic Equation in One Variable

Worksheet on Quadratic Formula

Worksheet on Nature of the Roots of a Quadratic Equation

Worksheet on Word Problems on Quadratic Equations by Factoring

9th Grade Math

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