Functions & inverse functions
Edexcel GCSE Maths revision on Functions & inverse functions. Aligned to the Pearson Edexcel GCSE Mathematics 1MA1 specification. This bank has 16 practice questions on this topic.
Sample questions (3 of 16)
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Question 1
Given the function f(x) = x + 7, what is the value of f(3)?
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Answer: 10
To find f(3), you replace x with 3 in the expression x + 7. Calculating 3 + 7 gives the result of 10.
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Question 2
Which expression represents the inverse function f^-1(x) for f(x) = x - 5?
- A) f^-1(x) = x + 5
- B) f^-1(x) = 5 - x
- C) f^-1(x) = x / 5
- D) f^-1(x) = 5 * x
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Answer: f^-1(x) = x + 5
To find the inverse, swap x and y and solve for y; x = y - 5 becomes y = x + 5. The distractor 5 - x incorrectly reverses the subtraction order.
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Question 3
If f(x) = 2x, what is the value of f(f(3))?
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Answer: 12
First, f(3) = 2 * 3 = 6. Then, you calculate f(6) = 2 * 6 = 12. This is a composite function where you apply the mapping twice.
Want to test yourself on the remaining cards for this topic?
13 more questions on Functions & inverse functions — plus mistakes tracking and spaced repetition across the whole Maths spec.