AlgebraKey Facts

Key Facts

Part of Inverse FunctionsGCSE Mathematics

This key facts covers Key Facts within Inverse Functions for GCSE Mathematics. Revise Inverse Functions in Algebra for GCSE Mathematics with 8 exam-style questions and 4 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 2 of 6 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 2 of 6

Practice

8 questions

Recall

4 flashcards

Key Facts

Concept Meaning Example
f(x) A function of x f(x) = 2x + 3
f⁻¹(x) Inverse function (undoes f) f⁻¹(x) = (x − 3)/2
Domain Input values for the function All real numbers (usually)
Range Output values from the function Depends on the function
One-to-one Each input gives a unique output Required for inverse to exist

Key insight: f(f⁻¹(x)) = x and f⁻¹(f(x)) = x

Keep building this topic

Read this section alongside the surrounding pages in Inverse Functions. That gives you the full topic sequence instead of a single isolated revision point.

Practice Questions for Inverse Functions

What does f⁻¹(x) represent?

  • A. The reciprocal of f(x), i.e. 1/f(x)
  • B. The function that undoes f(x)
  • C. The square of f(x)
  • D. The negative of f(x)
1 markfoundation

Explain why the function f(x) = x² (for all real x) does not have an inverse function over its full domain.

2 markshigher

Quick Recall Flashcards

What does f⁻¹ notation mean?
Inverse function (NOT 1/f). It's the function that undoes f, not the reciprocal
What is an inverse function?
A function that undoes what the original function does. f⁻¹(x) reverses the operation of f(x)

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