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Exam questions · Maths

Graphs

  • 30 exam questions
  • 94 marks
  • 45 quick checks

Straight-Line Graphs

Just this lesson
  1. 1 Calculate [2 marks]

    Calculate the gradient of the line through \((1, 2)\) and \((5, 10)\).

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    Model answer

    \(\dfrac{10 - 2}{5 - 1} = \dfrac{8}{4} = 2\).

    Mark scheme

    • \(\dfrac{10 - 2}{5 - 1}\) — M1
    • 2 — A1
  2. 2 Complete [3 marks]

    (a) Complete the table of values for \(y = 4x - 3\). \(x = 0, 1, 2, 3\) [2 marks] (b) Write down the \(y\)-intercept of the line \(y = 4x - 3\). [1 mark]

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    Model answer

    (a) The values are \(-3, 1, 5, 9\). (b) The \(y\)-intercept is \(-3\), where \(x = 0\).

    Mark scheme

    • (a) At least two correct values — M1
    • (a) \(-3, 1, 5, 9\) — A1
    • (b) \(-3\) — B1
  3. 3 Calculate [4 marks]

    The diagram shows a straight line passing through the points \(P\) and \(Q\). (a) Calculate the gradient of the line. [2 marks] (b) Write down the equation of the line. [2 marks]

    A steep straight line through the points P (1, 1) and Q (3, 7), crossing the y-axis at minus 2.
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    Model answer

    (a) \(\dfrac{7 - 1}{3 - 1} = \dfrac{6}{2} = 3\). (b) The line crosses the \(y\)-axis at \(-2\), so \(y = 3x - 2\).

    Mark scheme

    • (a) \(\dfrac{7 - 1}{3 - 1}\) — M1
    • (a) 3 — A1
    • (b) \(y = 3x + c\) or \(y = mx - 2\) — M1
    • (b) \(y = 3x - 2\) — A1
  4. 4 Find [2 marks]

    Find the equation of the line that is parallel to \(y = 3x - 7\) and passes through the point \((0, 2)\).

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    Model answer

    The gradient is 3 and the \(y\)-intercept is 2, so \(y = 3x + 2\).

    Mark scheme

    • Gradient 3 or \(c = 2\) used — M1
    • \(y = 3x + 2\) — A1
  5. 5 Find [3 marks]

    A straight line has gradient \(-2\) and passes through the point \((0, 5)\). (a) Write down the equation of the line. [1 mark] (b) Does the point \((4, -3)\) lie on the line? Show how you know. [2 marks]

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    Model answer

    (a) \(y = -2x + 5\). (b) When \(x = 4\), \(y = -2 \times 4 + 5 = -3\), so the point lies on the line.

    Mark scheme

    • (a) \(y = -2x + 5\) — B1
    • (b) \(-2 \times 4 + 5\) or \(-8 + 5\) — M1
    • (b) \(-3\) with a conclusion — A1
  6. 6 Show that [4 marks]

    \(A\) is the point \((-3, 2)\) and \(B\) is the point \((5, 6)\). (a) Work out the gradient of \(AB\). [2 marks] (b) Show that the line \(y = \dfrac{1}{2}x + 3.5\) passes through \(A\). [2 marks]

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    Model answer

    (a) \(\dfrac{6 - 2}{5 - (-3)} = \dfrac{4}{8} = \dfrac{1}{2}\). (b) When \(x = -3\), \(y = \dfrac{1}{2} \times (-3) + 3.5 = -1.5 + 3.5 = 2\), so the line passes through \(A\).

    Mark scheme

    • (a) \(\dfrac{6 - 2}{5 - (-3)}\) — M1
    • (a) \(\dfrac{1}{2}\) — A1
    • (b) \(\dfrac{1}{2} \times (-3) + 3.5\) — M1
    • (b) 2 with a conclusion — A1

Quick check

  1. 1

    What is the equation of the \(x\)-axis?

    1. A\(x = 0\)
    2. B\(y = 0\)
    3. C\(y = x\)
    4. D\(x + y = 0\)
    Show answerHide answer

    B: \(y = 0\)

    Every point on the \(x\)-axis has \(y = 0\).

  2. 2

    Which point is on the line \(y = 3x - 2\)?

    1. A\((4, 10)\)
    2. B\((2, 6)\)
    3. C\((1, 3)\)
    4. D\((0, 2)\)
    Show answerHide answer

    A: \((4, 10)\)

    Put in the coordinates: \(3 \times 4 - 2 = 10\), so \((4, 10)\) fits.

  3. 3

    Work out the gradient of the line through \((1, 7)\) and \((4, 1)\).

    1. A\(2\)
    2. B\(-\dfrac{1}{2}\)
    3. C\(-6\)
    4. D\(-2\)
    Show answerHide answer

    D: \(-2\)

    \(\dfrac{1 - 7}{4 - 1} = \dfrac{-6}{3} = -2\).

  4. 4

    Which line is parallel to \(y = 3x + 1\)?

    1. A\(y = x + 3\)
    2. B\(y = -3x + 1\)
    3. C\(y = 3x - 5\)
    4. D\(y = \dfrac{1}{3}x + 1\)
    Show answerHide answer

    C: \(y = 3x - 5\)

    Parallel lines have the same gradient, 3.

  5. 5

    What is the equation of the vertical line through 4 on the \(x\)-axis?

    1. A\(y = 4\)
    2. B\(x = 4\)
    3. C\(x + y = 4\)
    4. D\(y = x\)
    Show answerHide answer

    B: \(x = 4\)

    Every point on the line has \(x = 4\).

  6. 6

    What is the gradient of the line \(y = 5 - 3x\)?

    1. A\(-3\)
    2. B\(5\)
    3. C\(3\)
    4. D\(-5\)
    Show answerHide answer

    A: \(-3\)

    Written as \(y = -3x + 5\), the number multiplying \(x\) is \(-3\).

  7. 7

    What is the value of \(y\) on the line \(y = 2x - 1\) when \(x = -1\)?

    1. A\(-1\)
    2. B\(1\)
    3. C\(-2\)
    4. D\(-3\)
    Show answerHide answer

    D: \(-3\)

    \(2 \times (-1) - 1 = -2 - 1 = -3\).

  8. 8

    Where does the line \(y = 3x + 2\) cross the \(y\)-axis?

    1. A\((2, 0)\)
    2. B\((0, 3)\)
    3. C\((0, 2)\)
    4. D\((0, -2)\)
    Show answerHide answer

    C: \((0, 2)\)

    The number on its own, 2, is the \(y\)-intercept.

  9. 9

    Work out the gradient of the line through \((-2, 3)\) and \((4, -9)\).

    1. A\(2\)
    2. B\(-2\)
    3. C\(-\dfrac{1}{2}\)
    4. D\(-6\)
    Show answerHide answer

    B: \(-2\)

    \(\dfrac{-9 - 3}{4 - (-2)} = \dfrac{-12}{6} = -2\).

Equations of Straight Lines

Just this lesson
  1. 1 Calculate [2 marks]

    Calculate the midpoint of \((-3, -2)\) and \((5, 4)\).

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    Model answer

    \(\left(\dfrac{-3 + 5}{2}, \dfrac{-2 + 4}{2}\right) = (1, 1)\).

    Mark scheme

    • One coordinate correct — M1
    • \((1, 1)\) — A1
  2. 2 Calculate [5 marks]

    The diagram shows a straight line through the points \(A\) and \(B\). (a) Calculate the gradient of \(AB\). [2 marks] (b) Find the equation of \(AB\). [2 marks] (c) Find the coordinates of the midpoint of \(AB\). [1 mark]

    A straight line passing through the points A (0, 6) and B (4, 0).
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    Model answer

    (a) \(\dfrac{0 - 6}{4 - 0} = -\dfrac{3}{2}\). (b) The line crosses the \(y\)-axis at 6, so \(y = -\dfrac{3}{2}x + 6\). (c) \(\left(\dfrac{0 + 4}{2}, \dfrac{6 + 0}{2}\right) = (2, 3)\).

    Mark scheme

    • (a) \(\dfrac{0 - 6}{4 - 0}\) — M1
    • (a) \(-\dfrac{3}{2}\) — A1
    • (b) \(y = -\dfrac{3}{2}x + c\) or \(y = mx + 6\) — M1
    • (b) \(y = -\dfrac{3}{2}x + 6\) — A1
    • (c) \((2, 3)\) — B1
  3. 3 Find [3 marks]

    Find the equation of the line that is parallel to \(y = 4x + 1\) and passes through \((1, 9)\).

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    Model answer

    The gradient is 4, so \(y = 4x + c\). Putting in \((1, 9)\) gives \(9 = 4 + c\), so \(c = 5\) and \(y = 4x + 5\).

    Mark scheme

    • \(y = 4x + c\) — M1
    • \(9 = 4 \times 1 + c\) — M1
    • \(y = 4x + 5\) — A1
  4. 4 Find [3 marks]

    A line has equation \(2x - 3y = 12\). Find the coordinates of the points where the line crosses the \(x\)-axis and the \(y\)-axis.

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    Model answer

    When \(y = 0\), \(2x = 12\) and \(x = 6\), so the point is \((6, 0)\). When \(x = 0\), \(-3y = 12\) and \(y = -4\), so the point is \((0, -4)\).

    Mark scheme

    • \(y = 0\) or \(x = 0\) used — M1
    • \((6, 0)\) — A1
    • \((0, -4)\) — A1
  5. 5 Find [3 marks]

    A line has equation \(3y + x = 6\). Find the gradient of a line that is perpendicular to it.

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    Model answer

    Rearranging, \(3y = -x + 6\), so \(y = -\dfrac{1}{3}x + 2\) and the gradient is \(-\dfrac{1}{3}\). The perpendicular gradient is 3.

    Mark scheme

    • \(y = -\dfrac{1}{3}x + 2\) or the gradient \(-\dfrac{1}{3}\) — M1
    • Negative reciprocal used — M1
    • 3 — A1
  6. 6 Calculate [4 marks]

    \(A\) is the point \((3, -2)\) and \(B\) is the point \((-2, 10)\). (a) Calculate the coordinates of the midpoint of \(AB\). [2 marks] (b) Calculate the length of \(AB\). [2 marks]

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    Model answer

    (a) \(\left(\dfrac{3 + (-2)}{2}, \dfrac{-2 + 10}{2}\right) = (0.5, 4)\). (b) The differences are 5 and 12, so \(AB = \sqrt{5^2 + 12^2} = \sqrt{169} = 13\).

    Mark scheme

    • (a) One coordinate correct — M1
    • (a) \((0.5, 4)\) — A1
    • (b) \(\sqrt{5^2 + 12^2}\) — M1
    • (b) 13 — A1

Quick check

  1. 1

    What is the equation of the line through \((2, 1)\) and \((6, 9)\)?

    1. A\(y = 2x + 3\)
    2. B\(y = \dfrac{1}{2}x - 3\)
    3. C\(y = 2x - 3\)
    4. D\(y = -2x - 3\)
    Show answerHide answer

    C: \(y = 2x - 3\)

    The gradient is \(\dfrac{8}{4} = 2\). Then \(1 = 2 \times 2 + c\) gives \(c = -3\).

  2. 2

    What is the midpoint of \((2, 1)\) and \((6, 9)\)?

    1. A\((8, 10)\)
    2. B\((4, 5)\)
    3. C\((2, 4)\)
    4. D\((4, 8)\)
    Show answerHide answer

    B: \((4, 5)\)

    \(\left(\dfrac{2 + 6}{2}, \dfrac{1 + 9}{2}\right) = (4, 5)\).

  3. 3

    A line is parallel to \(y = 5x - 2\). What is its gradient?

    1. A\(5\)
    2. B\(-5\)
    3. C\(-\dfrac{1}{5}\)
    4. D\(\dfrac{1}{5}\)
    Show answerHide answer

    A: \(5\)

    Parallel lines have equal gradients.

  4. 4

    A line has gradient 3 and passes through \((2, 9)\). What is its equation?

    1. A\(y = 3x + 9\)
    2. B\(y = 3x - 3\)
    3. C\(y = 3x + 6\)
    4. D\(y = 3x + 3\)
    Show answerHide answer

    D: \(y = 3x + 3\)

    \(9 = 3 \times 2 + c\) gives \(c = 3\).

  5. 5

    What is the gradient of the line \(2y - 4x = 6\)?

    1. A\(4\)
    2. B\(3\)
    3. C\(2\)
    4. D\(-2\)
    Show answerHide answer

    C: \(2\)

    Rearranged, \(2y = 4x + 6\), so \(y = 2x + 3\).

  6. 6

    What is the midpoint of \((0, 4)\) and \((6, 10)\)?

    1. A\((6, 14)\)
    2. B\((3, 7)\)
    3. C\((3, 3)\)
    4. D\((6, 7)\)
    Show answerHide answer

    B: \((3, 7)\)

    \(\left(\dfrac{0 + 6}{2}, \dfrac{4 + 10}{2}\right) = (3, 7)\).

  7. 7

    Where does the line \(3x + 2y = 12\) cross the axes?

    1. A\((0, 6)\) and \((4, 0)\)
    2. B\((0, 4)\) and \((6, 0)\)
    3. C\((0, 12)\) and \((12, 0)\)
    4. D\((0, 3)\) and \((2, 0)\)
    Show answerHide answer

    A: \((0, 6)\) and \((4, 0)\)

    Put \(x = 0\) to get \(y = 6\), and \(y = 0\) to get \(x = 4\).

  8. 8

    What is the gradient of a line perpendicular to a line with gradient 4?

    1. A\(\dfrac{1}{4}\)
    2. B\(-4\)
    3. C\(4\)
    4. D\(-\dfrac{1}{4}\)
    Show answerHide answer

    D: \(-\dfrac{1}{4}\)

    Perpendicular gradients multiply to \(-1\), so the new gradient is \(-\dfrac{1}{4}\).

  9. 9

    What is the equation of the line perpendicular to \(y = 2x + 3\) through \((4, 1)\)?

    1. A\(y = -2x + 9\)
    2. B\(y = \dfrac{1}{2}x - 1\)
    3. C\(y = -\dfrac{1}{2}x + 3\)
    4. D\(y = -\dfrac{1}{2}x + 1\)
    Show answerHide answer

    C: \(y = -\dfrac{1}{2}x + 3\)

    The gradient is \(-\dfrac{1}{2}\). Then \(1 = -2 + c\), so \(c = 3\).

Quadratic Graphs

Just this lesson
  1. 1 Complete [2 marks]

    Complete the table of values for \(y = x^2 - 2x\). \(x = -1, 0, 1, 2, 3\)

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    Model answer

    The values are \(3, 0, -1, 0, 3\).

    Mark scheme

    • At least three correct values — M1
    • \(3, 0, -1, 0, 3\) — A1
  2. 2 Write down [4 marks]

    The diagram shows the graph of \(y = 4x - x^2\). (a) Write down the coordinates of the maximum point. [1 mark] (b) Use the graph to solve \(4x - x^2 = 0\). [2 marks] (c) Write down the equation of the line of symmetry. [1 mark]

    The graph of the curve y equals 4x minus x squared.
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    Model answer

    (a) The highest point is \((2, 4)\). (b) The curve crosses the \(x\)-axis at \(x = 0\) and \(x = 4\). (c) The line of symmetry is \(x = 2\).

    Mark scheme

    • (a) \((2, 4)\) — B1
    • (b) One of \(x = 0\) or \(x = 4\) — M1
    • (b) \(x = 0\) and \(x = 4\) — A1
    • (c) \(x = 2\) — B1
  3. 3 Find [3 marks]

    A curve has equation \(y = x^2 + 2x - 3\). (a) Write down the coordinates of the point where the curve crosses the \(y\)-axis. [1 mark] (b) Solve \(x^2 + 2x - 3 = 0\) to find where the curve crosses the \(x\)-axis. [2 marks]

    Show answerHide answer

    Model answer

    (a) \((0, -3)\). (b) \(x^2 + 2x - 3 = (x + 3)(x - 1) = 0\), so \(x = -3\) and \(x = 1\).

    Mark scheme

    • (a) \((0, -3)\) — B1
    • (b) \((x + 3)(x - 1)\) — M1
    • (b) \(x = -3\) and \(x = 1\) — A1
  4. 4 Find [3 marks]

    The curve \(y = x^2 - 4x + k\) has its turning point at \((2, -1)\). Find the value of \(k\).

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    Model answer

    At the turning point \(x = 2\) and \(y = -1\), so \(-1 = 2^2 - 4 \times 2 + k = -4 + k\) and \(k = 3\).

    Mark scheme

    • \(x = 2\) and \(y = -1\) substituted — M1
    • \(-1 = 4 - 8 + k\) — M1
    • 3 — A1
  5. 5 Calculate [3 marks]

    (a) Write \(x^2 - 10x + 7\) in the form \((x - a)^2 + b\). [2 marks] (b) Write down the coordinates of the turning point of the graph of \(y = x^2 - 10x + 7\). [1 mark]

    Show answerHide answer

    Model answer

    (a) \((x - 5)^2 - 25 + 7 = (x - 5)^2 - 18\). (b) The turning point is \((5, -18)\).

    Mark scheme

    • (a) \((x - 5)^2\) seen — M1
    • (a) \((x - 5)^2 - 18\) — A1
    • (b) \((5, -18)\) — B1
  6. 6 Find [2 marks]

    The graph of \(y = x^2 - 4x + 3\) crosses the \(x\)-axis at \(x = 1\) and \(x = 3\). Write down the values of \(x\) for which \(y\) is negative.

    Show answerHide answer

    Model answer

    The graph is a U shape, so it is below the \(x\)-axis between the roots: \(1 < x < 3\).

    Mark scheme

    • Between the roots 1 and 3 identified — M1
    • \(1 < x < 3\) — A1

Quick check

  1. 1

    What is the shape of the graph of a quadratic equation?

    1. AA straight line
    2. BAn S-shaped curve
    3. CTwo separate branches
    4. DA parabola, a smooth U or upside-down U
    Show answerHide answer

    D: A parabola, a smooth U or upside-down U

    Quadratic graphs are parabolas.

  2. 2

    What are the roots of a graph?

    1. AThe \(y\)-values where the curve crosses the \(y\)-axis
    2. BThe highest point of the curve
    3. CThe \(x\)-values where the curve crosses the \(x\)-axis
    4. DThe line of symmetry
    Show answerHide answer

    C: The \(x\)-values where the curve crosses the \(x\)-axis

    At the roots \(y = 0\), so the curve meets the \(x\)-axis.

  3. 3

    Work out \(y\) when \(x = -2\) on \(y = x^2 - 2x - 3\).

    1. A\(-3\)
    2. B\(5\)
    3. C\(1\)
    4. D\(-5\)
    Show answerHide answer

    B: \(5\)

    \((-2)^2 - 2 \times (-2) - 3 = 4 + 4 - 3 = 5\).

  4. 4

    What is the \(y\)-intercept of \(y = x^2 + 4x - 7\)?

    1. A\(-7\)
    2. B\(7\)
    3. C\(4\)
    4. D\(0\)
    Show answerHide answer

    A: \(-7\)

    Put \(x = 0\): \(y = -7\).

  5. 5

    The graph of \(y = x^2 - 2x - 3\) crosses the \(x\)-axis at \(-1\) and 3. What are the solutions of \(x^2 - 2x - 3 = 0\)?

    1. A\(x = 1\) and \(x = -3\)
    2. B\(x = -1\) and \(x = -3\)
    3. C\(x = 0\) and \(x = 2\)
    4. D\(x = -1\) and \(x = 3\)
    Show answerHide answer

    D: \(x = -1\) and \(x = 3\)

    The solutions are the \(x\)-values where \(y = 0\).

  6. 6

    A parabola crosses the \(x\)-axis at \(x = 1\) and \(x = 5\). What is its line of symmetry?

    1. A\(x = 2.5\)
    2. B\(x = 5\)
    3. C\(x = 3\)
    4. D\(x = -3\)
    Show answerHide answer

    C: \(x = 3\)

    The line of symmetry is halfway between the roots: \(\dfrac{1 + 5}{2} = 3\).

  7. 7

    The curve \(y = x^2 - 4x + 3\) crosses the \(x\)-axis at 1 and 3. What are the coordinates of its turning point?

    1. A\((2, 1)\)
    2. B\((2, -1)\)
    3. C\((-2, -1)\)
    4. D\((4, 3)\)
    Show answerHide answer

    B: \((2, -1)\)

    \(x = 2\) is halfway between the roots. Then \(y = 4 - 8 + 3 = -1\).

  8. 8

    Which line do you draw on the graph of \(y = x^2 - 2x - 3\) to solve \(x^2 - 2x - 3 = 2\)?

    1. A\(y = 2\)
    2. B\(x = 2\)
    3. C\(y = -3\)
    4. D\(y = 0\)
    Show answerHide answer

    A: \(y = 2\)

    Solutions are where the curve meets the horizontal line \(y = 2\).

  9. 9

    What are the coordinates of the turning point of \(y = (x - 3)^2 - 4\)?

    1. A\((-3, -4)\)
    2. B\((3, 4)\)
    3. C\((-3, 4)\)
    4. D\((3, -4)\)
    Show answerHide answer

    D: \((3, -4)\)

    In \(y = (x - a)^2 + b\) the turning point is \((a, b)\).

Cubic, Reciprocal and Other Graphs

Just this lesson
  1. 1 Match [3 marks]

    The diagram shows three graphs, \(A\), \(B\) and \(C\). The three equations are \(y = x^2\), \(y = 2x - 1\) and \(y = x^3 - 3x\). Match each equation to the correct graph. [3 marks]

    Three graphs: an S-shaped curve with two turning points, a U-shaped curve touching the origin and an upward-sloping line.
    Show answerHide answer

    Model answer

    Graph \(A\) is an S shape with a hill and a valley, so \(y = x^3 - 3x\). Graph \(B\) is a U shape touching the origin, so \(y = x^2\). Graph \(C\) is a straight line, so \(y = 2x - 1\).

    Mark scheme

    • \(A\) is \(y = x^3 - 3x\) — B1
    • \(B\) is \(y = x^2\) — B1
    • \(C\) is \(y = 2x - 1\) — B1
  2. 2 Complete [2 marks]

    Complete the table of values for \(y = x^3 - x\). \(x = -2, -1, 0, 1, 2\)

    Show answerHide answer

    Model answer

    The values are \(-6, 0, 0, 0, 6\).

    Mark scheme

    • At least three correct values — M1
    • \(-6, 0, 0, 0, 6\) — A1
  3. 3 Complete [3 marks]

    (a) Complete the table of values for \(y = \dfrac{12}{x}\). \(x = 1, 2, 3, 4, 6, 12\) [2 marks] (b) For which value of \(x\) is the graph of \(y = \dfrac{12}{x}\) not defined? [1 mark]

    Show answerHide answer

    Model answer

    (a) The values are \(12, 6, 4, 3, 2, 1\). (b) It is not defined at \(x = 0\), because you cannot divide by zero.

    Mark scheme

    • (a) At least four correct values — M1
    • (a) \(12, 6, 4, 3, 2, 1\) — A1
    • (b) \(x = 0\) — B1
  4. 4 Calculate [3 marks]

    A population of bacteria is 100 at the start. It doubles every hour, so after \(t\) hours it is \(P = 100 \times 2^t\). (a) Calculate \(P\) when \(t = 3\). [1 mark] (b) Calculate \(P\) when \(t = 5\). [1 mark] (c) Explain why the graph of \(P\) against \(t\) never touches the \(t\)-axis. [1 mark]

    Show answerHide answer

    Model answer

    (a) \(100 \times 8 = 800\). (b) \(100 \times 32 = 3200\). (c) \(2^t\) is always greater than 0, so \(P\) is never 0.

    Mark scheme

    • (a) 800 — B1
    • (b) 3200 — B1
    • (c) \(2^t\) is never zero, so the population is never 0 — C1
  5. 5 Calculate [3 marks]

    A curve has equation \(y = x^2 - 9\). (a) Calculate the coordinates of the points where the curve crosses the \(x\)-axis. [2 marks] (b) Write down the \(y\)-intercept. [1 mark]

    Show answerHide answer

    Model answer

    (a) When \(y = 0\), \(x^2 = 9\), so \(x = 3\) or \(x = -3\). The points are \((3, 0)\) and \((-3, 0)\). (b) The \(y\)-intercept is \(-9\).

    Mark scheme

    • (a) \(x^2 = 9\) — M1
    • (a) \((3, 0)\) and \((-3, 0)\) — A1
    • (b) \(-9\) — B1
  6. 6 Show that [3 marks]

    A circle has equation \(x^2 + y^2 = 13\). (a) Write down the radius of the circle in surd form. [1 mark] (b) Show that the point \((2, 3)\) lies on the circle. [2 marks]

    Show answerHide answer

    Model answer

    (a) The radius is \(\sqrt{13}\). (b) \(2^2 + 3^2 = 4 + 9 = 13\), so the point lies on the circle.

    Mark scheme

    • (a) \(\sqrt{13}\) — B1
    • (b) \(2^2 + 3^2\) or \(4 + 9\) — M1
    • (b) 13 with a conclusion — A1

Quick check

  1. 1

    What shape is the graph of \(y = x^3\)?

    1. AAn S-shaped curve through the origin
    2. BA U-shaped curve
    3. CTwo separate branches
    4. DA straight line
    Show answerHide answer

    A: An S-shaped curve through the origin

    Cubic graphs have an S shape.

  2. 2

    What is special about the graph of \(y = \dfrac{1}{x}\)?

    1. AIt passes through the origin
    2. BIt is a straight line
    3. CIt is a closed curve
    4. DIt has two branches and never touches either axis
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    D: It has two branches and never touches either axis

    You cannot divide by 0, and \(\dfrac{1}{x}\) is never 0.

  3. 3

    Where does the graph of \(y = 3^x\) cross the \(y\)-axis?

    1. A\((0, 3)\)
    2. B\((0, 0)\)
    3. C\((0, 1)\)
    4. D\((1, 0)\)
    Show answerHide answer

    C: \((0, 1)\)

    \(3^0 = 1\).

  4. 4

    What is the value of \(x^3\) when \(x = -3\)?

    1. A\(27\)
    2. B\(-27\)
    3. C\(-9\)
    4. D\(9\)
    Show answerHide answer

    B: \(-27\)

    \((-3) \times (-3) \times (-3) = -27\).

  5. 5

    Which of these equations gives a cubic graph?

    1. A\(y = x^3 + 1\)
    2. B\(y = 3x + 2\)
    3. C\(y = x^2 - 4\)
    4. D\(y = \dfrac{2}{x}\)
    Show answerHide answer

    A: \(y = x^3 + 1\)

    A cubic has \(x^3\) as its highest power.

  6. 6

    Work out \(y\) when \(x = 2\) on \(y = x^3 - 3x\).

    1. A\(14\)
    2. B\(-2\)
    3. C\(6\)
    4. D\(2\)
    Show answerHide answer

    D: \(2\)

    \(8 - 6 = 2\).

  7. 7

    What is \(2^3\)?

    1. A\(6\)
    2. B\(9\)
    3. C\(8\)
    4. D\(5\)
    Show answerHide answer

    C: \(8\)

    \(2 \times 2 \times 2 = 8\).

  8. 8

    What shape is the graph of \(y = -x^2\)?

    1. AA U shape
    2. BAn upside-down U
    3. CAn S shape
    4. DA straight line
    Show answerHide answer

    B: An upside-down U

    A negative \(x^2\) term turns the parabola upside down.

  9. 9

    What is the radius of the circle \(x^2 + y^2 = 36\)?

    1. A\(6\)
    2. B\(36\)
    3. C\(18\)
    4. D\(72\)
    Show answerHide answer

    A: \(6\)

    The radius is \(\sqrt{36} = 6\).

Real-Life Graphs

Just this lesson
  1. 1 Calculate [7 marks]

    The graph shows the velocity of a train during a 20 second journey. (a) Calculate the acceleration of the train in the first 5 seconds. [2 marks] (b) Calculate the deceleration of the train in the last 5 seconds. [2 marks] (c) Calculate the total distance travelled by the train. [3 marks]

    A velocity-time graph that speeds up to 10 m/s in 5 seconds, stays constant until 15 seconds and slows to 4 m/s at 20 seconds.
    Show answerHide answer

    Model answer

    (a) \(\dfrac{10}{5} = 2\) m/s\(^2\). (b) The velocity falls from 10 to 4 in 5 seconds, so \(\dfrac{10 - 4}{5} = 1.2\) m/s\(^2\). (c) The areas are \(\dfrac{1}{2} \times 5 \times 10 = 25\), \(10 \times 10 = 100\) and \(\dfrac{1}{2}(10 + 4) \times 5 = 35\), so the total is \(25 + 100 + 35 = 160\) m.

    Mark scheme

    • (a) \(\dfrac{10}{5}\) — M1
    • (a) 2 m/s\(^2\) — A1
    • (b) \(\dfrac{10 - 4}{5}\) — M1
    • (b) 1.2 m/s\(^2\) — A1
    • (c) At least two of 25, 100, 35 found — M1
    • (c) \(25 + 100 + 35\) — M1
    • (c) 160 m — A1
  2. 2 Calculate [3 marks]

    A gym charges a joining fee of \(\pounds 20\) and \(\pounds 15\) for each month of membership. (a) Calculate the total cost after 6 months. [1 mark] (b) Write a formula for the total cost \(C\) pounds after \(m\) months. [2 marks]

    Show answerHide answer

    Model answer

    (a) \(20 + 15 \times 6 = \pounds 110\). (b) \(C = 15m + 20\).

    Mark scheme

    • (a) \(\pounds 110\) — B1
    • (b) \(15m\) seen — M1
    • (b) \(C = 15m + 20\) — A1
  3. 3 Calculate [3 marks]

    A conversion graph from pounds to euros is a straight line through \((0, 0)\) and \((50, 60)\). (a) Calculate the gradient of the line. [2 marks] (b) What does the gradient represent? [1 mark]

    Show answerHide answer

    Model answer

    (a) \(\dfrac{60}{50} = 1.2\). (b) It is the number of euros for each pound, so \(\pounds 1 = \euro 1.20\).

    Mark scheme

    • (a) \(\dfrac{60}{50}\) — M1
    • (a) 1.2 — A1
    • (b) The number of euros for one pound — C1
  4. 4 Calculate [4 marks]

    A car slows down steadily from 20 m/s to rest in 8 seconds. (a) Calculate the deceleration of the car. [2 marks] (b) Calculate the distance travelled while it slows down. [2 marks]

    Show answerHide answer

    Model answer

    (a) \(\dfrac{20}{8} = 2.5\) m/s\(^2\). (b) The area of the triangle is \(\dfrac{1}{2} \times 8 \times 20 = 80\) m.

    Mark scheme

    • (a) \(\dfrac{20}{8}\) — M1
    • (a) 2.5 m/s\(^2\) — A1
    • (b) \(\dfrac{1}{2} \times 8 \times 20\) — M1
    • (b) 80 m — A1
  5. 5 Explain [2 marks]

    Water is poured at a steady rate into a bottle that is wide at the bottom and narrow at the top. Describe how the graph of depth against time changes as the bottle fills.

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    Model answer

    At first the bottle is wide, so the depth rises slowly and the graph is shallow. Near the top the bottle is narrow, so the depth rises quickly and the graph becomes steeper.

    Mark scheme

    • The graph starts shallow — C1
    • and gets steeper as the bottle fills — C1
  6. 6 Calculate [3 marks]

    The velocity of a runner is measured every 5 seconds. At times \(t = 0, 5, 10, 15\) seconds the velocity is \(v = 0, 8, 10, 4\) metres per second. Use trapezia to estimate the distance run in the 15 seconds.

    Show answerHide answer

    Model answer

    The areas of the three trapezia are \(\dfrac{1}{2} \times 5 \times 8 = 20\), \(\dfrac{1}{2} \times 5 \times (8 + 10) = 45\) and \(\dfrac{1}{2} \times 5 \times (10 + 4) = 35\). The total is \(20 + 45 + 35 = 100\) m.

    Mark scheme

    • One trapezium area found correctly — M1
    • \(20 + 45 + 35\) or equivalent — M1
    • 100 m — A1

Quick check

  1. 1

    On a conversion graph, 5 miles is about 8 km. About how many kilometres is 30 miles?

    1. A150 km
    2. B48 km
    3. C38 km
    4. D18.75 km
    Show answerHide answer

    B: 48 km

    30 miles is 6 lots of 5 miles, so \(6 \times 8 = 48\) km.

  2. 2

    What does the gradient of a velocity-time graph show?

    1. AAcceleration
    2. BDistance travelled
    3. CTime taken
    4. DTotal speed
    Show answerHide answer

    A: Acceleration

    Gradient is change in velocity divided by time, which is acceleration.

  3. 3

    What does the area under a velocity-time graph show?

    1. AAcceleration
    2. BSpeed
    3. CTime taken
    4. DDistance travelled
    Show answerHide answer

    D: Distance travelled

    Velocity multiplied by time gives distance.

  4. 4

    A car speeds up from 0 to 12 m/s in 4 seconds. What is its acceleration?

    1. A48 m/s\(^2\)
    2. B8 m/s\(^2\)
    3. C3 m/s\(^2\)
    4. D12 m/s\(^2\)
    Show answerHide answer

    C: 3 m/s\(^2\)

    \(\dfrac{12}{4} = 3\).

  5. 5

    A taxi costs \(\pounds 3\) plus \(\pounds 2\) for each kilometre. What is the cost of a 7 km journey?

    1. A\(\pounds 14\)
    2. B\(\pounds 17\)
    3. C\(\pounds 21\)
    4. D\(\pounds 10\)
    Show answerHide answer

    B: \(\pounds 17\)

    \(3 + 2 \times 7 = 17\).

  6. 6

    On a graph of taxi cost against distance, what does the \(y\)-intercept mean?

    1. AThe fixed starting charge
    2. BThe cost per kilometre
    3. CThe total cost
    4. DThe longest journey
    Show answerHide answer

    A: The fixed starting charge

    The intercept is the cost for 0 km.

  7. 7

    A container gets wider towards the top and is filled at a steady rate. What happens to the depth-time graph?

    1. AIt is a straight line
    2. BIt gets steeper and steeper
    3. CIt is horizontal
    4. DIt rises more and more slowly, so it flattens
    Show answerHide answer

    D: It rises more and more slowly, so it flattens

    The wider the container, the more slowly the depth rises.

  8. 8

    A velocity-time graph is a triangle that rises from 0 to 8 m/s in 5 seconds. What distance does it show?

    1. A40 m
    2. B13 m
    3. C20 m
    4. D1.6 m
    Show answerHide answer

    C: 20 m

    Area \(= \dfrac{1}{2} \times 5 \times 8 = 20\).

  9. 9

    How can you estimate the speed at one moment from a curved distance-time graph?

    1. AFind the area under the curve
    2. BDraw a tangent and find its gradient
    3. CRead the highest point
    4. DRead the value at the end
    Show answerHide answer

    B: Draw a tangent and find its gradient

    The gradient of the tangent is the rate of change at that point.