GCSE · Functions

Function notationExam-style questions

Why f(x) is a machine's output, not a multiplication — evaluating f(3), reading f(x) = k as an equation to solve, and keeping inputs and outputs straight.

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11 questions · GCSE (Higher) level · mark scheme and worked solution on each · no sign-up to try

DifficultyAllLevel 2Level 3Level 4Level 5
  1. 1
    f(x)=5x−4\mathrm{f}(x) = 5x - 4

    (a) Work out f(3)\mathrm{f}(3). [1]

    (b) Find f−1(x)\mathrm{f}^{-1}(x). [2]

    (c) Solve f(x)=f−1(x)\mathrm{f}(x) = \mathrm{f}^{-1}(x). [1]
    Level 3 · 4 marksTry it
  2. 2
    f(x)=3x−4f(x) = 3x - 4

    (a) Work out f(5)f(5)

    (b) Work out f(−2)f(-2)

    (c) Solve f(x)=20f(x) = 20
    Level 3 · 4 marksTry it
  3. 3
    h(x)=x−32h(x) = \dfrac{x - 3}{2}

    (a) Work out h(11)h(11)

    (b) Solve h(x)=−5h(x) = -5
    Level 3 · 3 marksTry it
  4. 4
    g(x)=10−3xg(x) = 10 - 3x

    (a) Work out g(4)g(4)

    (b) Solve g(x)=−8g(x) = -8
    Level 3 · 3 marksTry it