This key facts covers Key Notation within Function Notation for GCSE Mathematics. Revise Function Notation in Algebra for GCSE Mathematics with 10 exam-style questions and 3 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 2 of 5 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 5
Practice
10 questions
Recall
3 flashcards
Key Notation
| Notation | Meaning | Example (if f(x) = 2x + 1) |
|---|---|---|
| f(x) | The function rule | f(x) = 2x + 1 |
| f(3) | Output when input is 3 | f(3) = 2(3) + 1 = 7 |
| f⁻¹(x) | Inverse function | f⁻¹(x) = (x − 1)/2 |
| fg(x) | Composite: f of g(x) | Do g first, then f |
Keep building this topic
Read this section alongside the surrounding pages in Function Notation. That gives you the full topic sequence instead of a single isolated revision point.
Practice Questions for Function Notation
If f(x) = x² − 1, what does f(3) equal?
f(x) = x + 3 and g(x) = 2x. Show with an example that fg(x) ≠ gf(x), and explain why the order matters.
Quick Recall Flashcards
10 questions on Function Notation — practise free
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