Exponential growth & decay graphs
AQA GCSE Maths revision on Exponential growth & decay graphs. Aligned to the AQA GCSE Mathematics 8300 specification. This bank has 16 practice questions on this topic.
Sample questions (3 of 16)
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Question 1
Which of these functions represents a standard exponential decay graph where the y-intercept is positive?
- A) y = 5 times 0.5 to the power of x
- B) y = 5 times 1.5 to the power of x
- C) y = 0.5 times 5 to the power of x
- D) y = 1.5 times 5 to the power of x
Show answer
Answer: y = 5 times 0.5 to the power of x
The correct answer is y = 5 times 0.5 to the power of x, as a base between 0 and 1 indicates decay. If the base is greater than 1, the graph represents exponential growth, which is why the other options are incorrect.
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Question 2
What is the y-intercept of the exponential growth function y = 12 times 3 to the power of x?
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Answer: 12
The y-intercept is 12. Since any number raised to the power of 0 is 1, substituting x = 0 into the equation gives y = 12 times 1, which equals 12.
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Question 3
Which statement correctly describes the horizontal asymptote of the graph y = 4 to the power of x?
- A) The line y = 0 acts as a limit
- B) The line x = 0 acts as a limit
- C) The line y = 1 acts as a limit
- D) The line x = 1 acts as a limit
Show answer
Answer: The line y = 0 acts as a limit
The correct answer is the line y = 0 acts as a limit. As x approaches negative infinity, the value of 4 to the power of x becomes infinitely small but never reaches zero, creating a horizontal asymptote.
Want to test yourself on the remaining cards for this topic?
13 more questions on Exponential growth & decay graphs — plus mistakes tracking and spaced repetition across the whole Maths spec.