GCSE · Graphs of functions

Transformations of graphs (y = f(x) + a, y = f(x + a), y = −f(x), y = f(−x))Exam-style questions

Move a graph without plotting it again. A number added outside the f moves the curve up or down; a number added inside the bracket moves it sideways, the opposite way to its sign; a minus sign outside reflects it in the x-axis and a minus sign inside reflects it in the y-axis. Track the key points, describe each change fully, combine two changes, write the new equation, and use the same four rules on the sine and cosine waves.

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

DifficultyAllLevel 2Level 3Level 4Level 5
  1. 1
    The graph of y=f(x)y = \mathrm{f}(x) has a maximum point at (−2,5)(-2, 5)

    Write down the coordinates of the turning point of the graph of
    (a) y=f(x)−7y = \mathrm{f}(x) - 7

    (1 mark)
    (b) y=f(x+3)y = \mathrm{f}(x + 3)

    (1 mark)
    (c) y=−f(x)y = -\mathrm{f}(x)

    (1 mark)
    (d) y=f(−x)y = \mathrm{f}(-x)

    (1 mark)
    Level 3 · 4 marksTry it
  2. 2
    (a) The sketch shows the graph of y=sin⁡x+ay = \sin x + a for 0°≤x≤360°0° \le x \le 360°, where aa is a constant.(90°, −1)(270°, −3)90180270360xyWrite down the value of aa.

    (1 mark)
    (b) The sketch shows the graph of y=cos⁡(x+b)y = \cos(x + b) for 0°≤x≤360°0° \le x \le 360°, where 0<b<1800 < b < 180(120°, −1)90180270360xyFind the value of bb.

    (2 marks)
    Level 3 · 3 marksTry it
  3. 3
    Here is a question and an incorrect solution.

    Question: Describe fully the single transformation that maps the graph of y=x2y = x^2 onto the graph of y=(x+5)2−2y = (x + 5)^2 - 2

    Solution: Translation by the vector (5−2)\begin{pmatrix} 5 \\ -2 \end{pmatrix}
    (a) Describe the error made.

    (1 mark)
    (b) Write down the correct vector.

    (1 mark)
    (c) Write down the coordinates of the turning point of the graph of y=(x+5)2−2y = (x + 5)^2 - 2

    (1 mark)
    Level 3 · 3 marksTry it
  4. 4
    The graph of y=cos⁡xy = \cos x is translated 90°90° to the right.
    (a) Write down the equation of the new graph.

    (1 mark)
    (b) Write down the coordinates of the point where the new graph crosses the yy-axis.

    (1 mark)
    (c) Asha says,

    "The new graph is the graph of y=sin⁡xy = \sin x"

    Is she correct?

    Give a reason for your answer.

    (1 mark)
    Level 3 · 3 marksTry it
  5. 5
    The curve CC has equation y=x2+2x−8y = x^2 + 2x - 8

    CC is translated by the vector (30)\begin{pmatrix} 3 \\ 0 \end{pmatrix} to give the curve DD.

    Find the equation of DD.

    Give your answer in the form y=x2+bx+cy = x^2 + bx + c

    You must show your working.

    (3 marks)
    Level 3 · 3 marksTry it

2 more questions on transformations of graphs (y = f(x) + a, y = f(x + a), y = −f(x), y = f(−x))

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