Lesson F2

F2 Exponential model and the gradient of e to the kx Quiz: AQA Maths, Unit 6

20 questions

In partnership with Revision Ninja

Lesson F2, Exponential model and the gradient of e to the kx: 20 multiple choice questions for the AQA Maths (7357), Unit 6: Exponentials and logarithms, written with Revision Ninja.

Host it live on the board and students join with a game code on their own devices, or revise alone with Free Play. The answers are revealed in the game.

Host this setFree Play

The 20 questions

  1. What is the derivative of e^(kx) with respect to x?

    • e^(kx)/k
    • k x e^(kx - 1)
    • e^x / k
    • k e^(kx)
  2. What is the gradient of y = e^(3x) at x = 0?

    • 0
    • e^3
    • 1
    • 3
  3. Which property makes e^(kx) suitable for modelling many growth processes?

    • Its values repeat with a fixed period
    • Its rate of change is proportional to its current value
    • Its rate of change is constant at every value of x
    • Its gradient is always zero at x = 0
  4. Find dy/dx for y = 5e^(-2x).

    • 10e^(-2x)
    • -2e^(-2x)
    • 5e^(-2x)
    • -10e^(-2x)
  5. If y = A e^(kx) with k > 0 and A > 0, what happens to y as x increases?

    • It decays towards zero
    • It grows without limit
    • It oscillates between positive and negative values
    • It approaches A from above and stays bounded
  6. The curve y = e^(2x) passes through the point where y = 4. What is the gradient there?

    • 8
    • 2
    • 4
    • 16
  7. For y = e^(kx), the gradient at x = ln 2 / k is which value?

    • k
    • 2
    • ln 2
    • 2k
  8. A population is modelled by P = 100 e^(0.05t), with t in years. What is dP/dt when t = 0?

    • 0.05
    • 100
    • 105
    • 5
  9. A quantity satisfies N = 50 e^(0.2t). What is the rate of change of N when N = 100?

    • 20
    • 0.2
    • 10
    • 50
  10. A temperature model is T = 20 + 60 e^(-0.1t). What is dT/dt at t = 0?

    • 6
    • -0.1
    • -60
    • -6
  11. A car value is V = 12000 e^(-0.15t) pounds, with t in years. What is the initial rate of change of V?

    • -12000 pounds per year
    • -0.15 pounds per year
    • 1800 pounds per year
    • -1800 pounds per year
  12. Which statement about y = e^(-kt) with k > 0 is correct?

    • It increases and approaches 1 as t tends to infinity
    • It reaches zero at a finite time t
    • It decreases towards zero as t increases, and its gradient is always negative
    • Its gradient is positive for all values of t
  13. For y = 3e^(2x), find the gradient at the point where y = 6.

    • 3
    • 12
    • 6
    • 24
  14. Which function satisfies dy/dx = 2y with y = 5 when x = 0?

    • y = 5x^2
    • y = 2e^(5x)
    • y = 10e^x
    • y = 5e^(2x)
  15. A quantity Q = Q0 e^(-kt) halves in time T. Which expression gives T?

    • T = 2k
    • T = k ln(1/2)
    • T = ln 2 / k
    • T = k / ln 2
  16. For y = e^(kx), the gradient at x = 2 equals 3 times the value of y there. What is k?

    • 2
    • 3
    • 6
    • 1/3
  17. Which limitation applies to an exponential growth model of a population over a long period?

    • Exponential models always give negative population values
    • The model gives a constant population for all times
    • Resources are limited, so growth slows and the model overestimates the population
    • Population cannot grow at all in an exponential model
  18. The gradient of y = e^(kx) at the point (0, 1) is 4. What is k?

    • e^4
    • 1/4
    • ln 4
    • 4
  19. For y = e^(3x), find d^2y/dx^2.

    • e^(9x)
    • 6e^(3x)
    • 9e^(3x)
    • 3e^(3x)
  20. A quantity doubles every 5 years and follows Q = Q0 e^(kt). What is k to 3 significant figures?

    • 0.322
    • 5 ln 2
    • 0.400
    • 0.139

All AQA Maths quizzes