Q. Determine the product of the roots of the equation x² + 6x + 8 = 0. (2023)
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Solution
The product of the roots is given by c/a = 8/1 = 8.
Correct Answer:
A
— 8
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Q. Determine the product of the roots of the equation x² + 6x + 9 = 0. (2021)
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Solution
The product of the roots is c/a = 9/1 = 9.
Correct Answer:
A
— 9
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Q. Determine the roots of the equation x² + 2x - 8 = 0. (2023)
A.
-4 and 2
B.
4 and -2
C.
2 and -4
D.
0 and 8
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Solution
Factoring gives (x + 4)(x - 2) = 0, hence the roots are -4 and 2.
Correct Answer:
A
— -4 and 2
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Q. Determine the roots of the equation x² + 6x + 9 = 0. (2023)
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Solution
This is a perfect square: (x + 3)² = 0, hence the root is x = -3.
Correct Answer:
A
— -3
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Q. Find the roots of the equation 3x² - 12x + 12 = 0. (2021)
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Solution
Dividing by 3 gives x² - 4x + 4 = 0, which factors to (x - 2)² = 0, hence the root is 2.
Correct Answer:
A
— 2
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Q. Find the roots of the equation 4x² - 12x + 9 = 0. (2023)
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Solution
This is a perfect square: (2x - 3)² = 0, hence the root is x = 1.5.
Correct Answer:
B
— 2
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Q. Find the roots of the equation x² + 2x - 8 = 0. (2022)
A.
-4 and 2
B.
4 and -2
C.
2 and -4
D.
0 and 8
Show solution
Solution
Factoring gives (x + 4)(x - 2) = 0, hence the roots are 4 and -2.
Correct Answer:
B
— 4 and -2
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Q. Find the value of k for which the equation x² + 4x + k = 0 has no real roots. (2020)
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Solution
The discriminant must be negative: 4² - 4*1*k < 0, which gives k > 4, so the minimum value is -6.
Correct Answer:
B
— -6
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Q. Find the value of k for which the equation x² + kx + 16 = 0 has equal roots. (2022)
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Solution
For equal roots, the discriminant must be zero: k² - 4*1*16 = 0, thus k² = 64, k = ±8. The value of k can be -8.
Correct Answer:
A
— -8
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Q. Find the value of k for which the equation x² + kx + 9 = 0 has no real roots. (2023)
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Solution
For no real roots, the discriminant must be negative: k² - 4*1*9 < 0, thus k² < 36, hence k < -6 or k > 6.
Correct Answer:
A
— -6
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Q. Find the value of k if the equation x² + kx + 16 = 0 has no real roots. (2022)
A.
k < 8
B.
k > 8
C.
k < 0
D.
k > 0
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Solution
For no real roots, the discriminant must be less than zero: k² - 4*1*16 < 0, which gives k > 8.
Correct Answer:
B
— k > 8
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Q. For the equation x² + 4x + k = 0 to have real roots, what must be the minimum value of k? (2023)
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Solution
The discriminant must be non-negative: 4² - 4*1*k ≥ 0, thus k ≤ 4.
Correct Answer:
A
— -4
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Q. For the equation x² + 6x + k = 0 to have real roots, what is the minimum value of k? (2021)
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Solution
The discriminant must be non-negative: 6² - 4*1*k ≥ 0, which gives k ≤ 9, so the minimum value is -9.
Correct Answer:
A
— -9
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Q. For the equation x² + 6x + k = 0 to have real roots, what must be the minimum value of k? (2023)
A.
-9
B.
-6
C.
-12
D.
-15
Show solution
Solution
The discriminant must be non-negative: 6² - 4*1*k ≥ 0, thus k ≤ 9.
Correct Answer:
A
— -9
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Q. For the quadratic equation x² + 2x + k = 0 to have real roots, what is the condition on k? (2021)
A.
k ≥ 1
B.
k ≤ 1
C.
k > 1
D.
k < 1
Show solution
Solution
The discriminant must be non-negative: 2² - 4*1*k ≥ 0, which simplifies to k ≤ 1.
Correct Answer:
B
— k ≤ 1
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Q. For the quadratic equation x² + 6x + k = 0 to have no real roots, what must be the value of k? (2021)
A.
k < 9
B.
k > 9
C.
k = 9
D.
k ≤ 9
Show solution
Solution
The discriminant must be less than zero: 6² - 4*1*k < 0, which simplifies to k > 9.
Correct Answer:
B
— k > 9
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Q. For the quadratic equation x² + 6x + k = 0 to have real roots, what is the minimum value of k? (2021)
Show solution
Solution
The discriminant must be non-negative: 6² - 4*1*k ≥ 0, thus k ≤ 9. The minimum value of k is -9.
Correct Answer:
A
— -9
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Q. For which value of k does the equation x² - kx + 9 = 0 have no real roots? (2021)
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Solution
The discriminant must be less than zero: k² - 4*1*9 < 0, thus k² < 36, so k > 6 or k < -6.
Correct Answer:
A
— 6
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Q. For which value of k does the equation x² - kx + 9 = 0 have roots that are both positive? (2023)
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Solution
For both roots to be positive, k must be greater than 0 and k² > 4*9 = 36, thus k > 6.
Correct Answer:
B
— 8
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Q. For which value of m does the equation x² + mx + 9 = 0 have roots that are both negative? (2021)
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Solution
For both roots to be negative, m must be greater than 0 and m² < 36. Thus, m must be in the range (-6, 0). The suitable value is -4.
Correct Answer:
B
— -4
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Q. For which value of m does the equation x² - mx + 9 = 0 have roots 3 and 3? (2023)
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Solution
The sum of the roots is 3 + 3 = 6, hence m = 6.
Correct Answer:
A
— 6
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Q. For which value of p does the equation x² + px + 4 = 0 have roots 2 and -2? (2022)
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Solution
Using the sum of roots: 2 + (-2) = -p, hence p = 0.
Correct Answer:
C
— -4
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Q. For which value of p does the equation x² + px + 4 = 0 have roots that are both negative? (2022)
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Solution
For both roots to be negative, p must be greater than 0 and p² > 16. Thus, p < -4.
Correct Answer:
C
— -4
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Q. For which value of p does the equation x² + px + 9 = 0 have roots that are both negative? (2021)
Show solution
Solution
For both roots to be negative, p must be positive and p² > 4*9. Thus, p > 6, so p = -4 is valid.
Correct Answer:
B
— -4
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Q. For which value of p does the equation x² - px + 9 = 0 have roots 3 and 3? (2021)
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Solution
The sum of the roots is 3 + 3 = 6, hence p = 6.
Correct Answer:
A
— 6
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Q. If one root of the equation x² - 6x + k = 0 is 2, find k. (2022)
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Solution
Using the root 2 in the equation: 2² - 6*2 + k = 0, we find k = 10.
Correct Answer:
B
— 10
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Q. If one root of the equation x² - 7x + k = 0 is 3, find k. (2023)
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Solution
Using the root, substitute x = 3: 3² - 7*3 + k = 0, which gives k = 10.
Correct Answer:
A
— 10
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Q. If one root of the equation x² - 7x + k = 0 is 3, what is the value of k? (2020)
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Solution
Using the root, substitute x = 3: 3² - 7*3 + k = 0, which gives k = 9.
Correct Answer:
D
— 9
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Q. If one root of the equation x² - 7x + p = 0 is 3, what is the value of p? (2020)
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Solution
Using the root, substitute x = 3: 3² - 7*3 + p = 0, which gives p = 6.
Correct Answer:
B
— 9
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Q. If the quadratic equation x² + 5x + k = 0 has roots -2 and -3, find k. (2020)
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Solution
The product of the roots gives k = (-2)(-3) = 6.
Correct Answer:
A
— 6
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Showing 1 to 30 of 79 (3 Pages)
Quadratic Equations MCQ & Objective Questions
Quadratic equations are a fundamental part of mathematics that students encounter in their academic journey. Mastering this topic is crucial for excelling in school exams and competitive tests. Practicing MCQs and objective questions on quadratic equations not only enhances your understanding but also boosts your confidence, enabling you to score better in exams.
What You Will Practise Here
Understanding the standard form of quadratic equations.
Identifying roots using the quadratic formula.
Factoring quadratic equations and solving them.
Graphical representation of quadratic functions.
Applications of quadratic equations in real-life problems.
Discriminant and its significance in determining the nature of roots.
Common word problems related to quadratic equations.
Exam Relevance
Quadratic equations are a staple in various examinations, including CBSE, State Boards, NEET, and JEE. Students can expect questions that require them to solve equations, analyze graphs, and apply concepts to real-world scenarios. Common question patterns include multiple-choice questions, fill-in-the-blanks, and problem-solving tasks that test both conceptual understanding and application skills.
Common Mistakes Students Make
Confusing the signs when applying the quadratic formula.
Overlooking the importance of the discriminant in determining the nature of roots.
Failing to check for extraneous solutions after solving equations.
Misinterpreting word problems that involve quadratic equations.
FAQs
Question: What is the standard form of a quadratic equation?Answer: The standard form of a quadratic equation is ax² + bx + c = 0, where a, b, and c are constants, and a ≠ 0.
Question: How do I find the roots of a quadratic equation?Answer: You can find the roots using the quadratic formula: x = (-b ± √(b² - 4ac)) / (2a).
Now is the time to enhance your skills! Dive into our practice MCQs on quadratic equations and test your understanding. Remember, consistent practice is key to mastering this topic and achieving success in your exams!