Lesson I1

I1 Locating roots by change of sign Quiz: AQA Maths, Unit 9

20 questions

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Lesson I1, Locating roots by change of sign: 20 multiple choice questions for the AQA Maths (7357), Unit 9: Numerical methods, written with Revision Ninja.

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The 20 questions

  1. If a continuous function has opposite signs at interval endpoints, what exists between them?

    • A maximum point
    • At least one root
    • Exactly one root
    • No roots
  2. Why can a sign-change method fail to detect a double root of f(x) = 0?

    • No sign change
    • Multiple y-intercepts
    • Infinite gradient
    • Discontinuous function
  3. What condition must a function satisfy for a sign change to guarantee a root?

    • Continuous
    • Differentiable
    • Increasing
    • Linear
  4. If f(a) and f(b) have the same sign, how many roots are in (a, b)?

    • Exactly zero roots
    • Exactly one root
    • No definite conclusion
    • Exactly two roots
  5. Which interval must contain a root of x^3 - x - 1 = 0 by change of sign?

    • (-1, 0)
    • (2, 3)
    • (0, 1)
    • (1, 2)
  6. Which of these intervals shows a change of sign for f(x) = x^2 - 3?

    • (0, 1)
    • (3, 4)
    • (4, 5)
    • (1, 2)
  7. Which interval must contain a root of x^3 - 2x - 5 = 0?

    • (2, 3)
    • (-1, 0)
    • (0, 1)
    • (3, 4)
  8. Which interval must contain a root of cos x - x = 0?

    • (0, 1)
    • (2, 3)
    • (-1, 0)
    • (1, 2)
  9. Which interval must contain a root of ln x + x - 2 = 0?

    • (0, 1)
    • (3, 4)
    • (1, 2)
    • (2, 3)
  10. Which interval must contain a root of x^3 - 4x + 1 = 0?

    • (-1, 0)
    • (3, 4)
    • (0, 1)
    • (1, 1.5)
  11. Which intervals contain the positive root of x^2 - 2x - 1 = 0?

    • (2, 3)
    • (3, 4)
    • (4, 5)
    • (1, 2)
  12. Why does sign change fail to guarantee a root for f(x) = 1/x on [-1, 1]?

    • Function is non-differentiable
    • Function is stationary
    • Roots are complex
    • Function is discontinuous
  13. For f(x) = x^3 - 2 on [1, 2], what is the new interval after one bisection step?

    • [0, 1]
    • [1.5, 2]
    • [1, 1.5]
    • [1, 2.5]
  14. The equation 1/x - 2 = 0 has a root in [0.25, 1]. What is the root?

    • x = 2
    • x = 1
    • x = 0.25
    • x = 0.5
  15. Which interval must contain a root of x^3 - 7 = 0?

    • (0, 1)
    • (-2, -1)
    • (2, 3)
    • (1, 2)
  16. Which interval must contain a root of x^2 - 2x - 1 = 0 for the negative root, using f(-1) = 2 and f(0) = -1?

    • (0, 1)
    • (-1, 0)
    • (-2, -1)
    • (1, 2)
  17. For f(x) = x^3 - 2x - 1, which interval must contain a root?

    • (-3, -2)
    • (1, 2)
    • (0, 1)
    • (2, 3)
  18. Which interval must contain a root of x^3 + x - 3 = 0?

    • (-2, -1)
    • (1, 2)
    • (2, 3)
    • (0, 1)
  19. What does a sign change of a continuous function across an interval guarantee?

    • At least one root
    • No real solutions
    • An asymptote
    • A local maximum
  20. Why can sign change fail to locate the root of f(x) = (x - 2)^2?

    • It is complex
    • It is undefined
    • It is repeated
    • It is discontinuous

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