Robinson Tuition
Year 9 · Key Stage 3 · free KS3 maths worksheet

Quadratic, cubic, reciprocal and circle graphs

13 original questions, 49 marks. Type your answers below for an instant mark and a score (algebra in any equivalent form, e.g. 2sqrt(3) or 2√3), or print the worksheet, mark it with the answers sheet, and use the solutions to see every step written out by hand.

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The questions

1

The curve y = x2 - 6x + 8 crosses the x-axis at x = 2 and at x = 4.

  1. Write down the solutions of x2 - 6x + 8 = 0
  2. Write down the x-coordinate of the turning point of the curve.
0123456−2−112345678910xy
2 marks
Show answer
a) x = 2 and x = 4 b) x = 3
2

Here is a table of values for y = x2 + x − 2

x−3−2−1012
y4−24
  1. Complete the table.
  2. On the grid, draw the graph of y = x2 + x − 2 for values of x from −3 to 2
−4−3−2−1123−3−2−112345Oxy
4 marks
Show answer
a) 0, -2, 0 b) smooth U-shaped curve through (-3, 4), (-2, 0), (-1, -2), (0, -2), (1, 0), (2, 4)
3

The diagram shows the graph of y = x2 - 2x - 3

  1. Write down the coordinates of the point where the graph crosses the y-axis.
  2. Write down the solutions of x2 - 2x - 3 = 0
  3. Write down the coordinates of the turning point of the graph.
−3−2−112345−5−4−3−2−1123456Oxy
3 marks
Show answer
a) (0, -3) b) x = -1 and x = 3 c) (1, -4)
4

The graph of y = x2 − 4x + 1 is drawn on the grid.

  1. Write down the equation of the line of symmetry of the graph.
  2. Write down the coordinates of the turning point.
  3. Use the graph to estimate the solutions of x2 − 4x + 1 = 0
  4. Use the graph to estimate the solutions of x2 − 4x + 1 = 2
−112345−4−3−2−11234567Oxy
4 marks
Show answer
a) x = 2 b) (2, -3) c) x ≈ 0.3 and x ≈ 3.7 d) x ≈ -0.2 and x ≈ 4.2
5

The diagram shows five sketch graphs, labelled A, B, C, D and E.

Match each equation below to the letter of its graph.

  1. y = -x2
  2. y = x3
  3. y = 5x
xyAxyBxyCxyDxyE
3 marks
Show answer
a) C b) D c) E
6

Here is a table of values for y = 6x

x0.512346
y62
  1. Complete the table.
  2. On the grid, draw the graph of y = 6x for values of x from 0.5 to 6
  3. Explain why the graph never meets the y-axis.
01234567012345678910111213xy
4 marks
Show answer
a) 12, 3, 1.5, 1 b) smooth curve through (0.5, 12), (1, 6), (2, 3), (3, 2), (4, 1.5), (6, 1) c) on the y-axis x = 0, and 6 ÷ 0 cannot be worked out
7

Here is a table of values for y = x3 − 4x + 1

x−2−1012
y11
  1. Complete the table.
  2. On the grid, draw the graph of y = x3 − 4x + 1 for values of x from −2 to 2
−3−2−1123−3−2−112345Oxy
4 marks
Show answer
a) 4, -2, 1 b) smooth curve through (-2, 1), (-1, 4), (0, 1), (1, -2), (2, 1)
8

Kwame throws a ball straight up into the air. Its height, h metres, after t seconds is given by h = 20t − 5t2

The graph of h against t is drawn on the grid.

  1. Write down the greatest height of the ball, and the time when it reaches this height.
  2. Use the graph to find the two times when the ball is 15 m high.
  3. How long is the ball in the air?
012340510152025Time, t (seconds)Height, h (m)
4 marks
Show answer
a) 20 m, after 2 seconds b) 1 second and 3 seconds c) 4 seconds
9

The graph of y = x3 − 6x2 + 9x is drawn on the grid.

  1. Use the graph to write down the solutions of x3 − 6x2 + 9x = 0
  2. Use the graph to estimate the three solutions of x3 − 6x2 + 9x = 2
−112345−2−112345678Oxy
4 marks
Show answer
a) x = 0 and x = 3 b) x ≈ 0.3, x = 2 and x ≈ 3.7
10
  1. On the grid, draw the graph of x2 + y2 = 16
  2. Write down the radius of the circle x2 + y2 = 49
  3. Does the point (2, 3) lie inside, on or outside the circle x2 + y2 = 16? Show how you decide.
−5−4−3−2−112345−5−4−3−2−112345Oxy
4 marks
Show answer
a) circle with centre (0, 0) and radius 4 b) 7 c) inside, because 22 + 32 = 13, which is less than 16
11
  1. On the axes, sketch the graph of y = 6x for negative and positive values of x
  2. Write down the coordinates of any points where the graph crosses the coordinate axes.
−6−5−4−3−2−1123456−6−5−4−3−2−1123456Oxy
4 marks
Show answer
a) reciprocal curve with one branch in the first quadrant and one branch in the third quadrant, approaching but never touching the axes b) There are no such points - the graph never crosses the axes

Extension questions: beyond the core Year 9 objectives, for pupils who want a stretch.

12

The graph of y = x2 − 3x is drawn on the grid.

  1. Use the graph to solve x2 − 3x = 0
  2. By drawing a suitable straight line on the grid, estimate the solutions of x2 − 4x − 1 = 0
−112345−3−2−112345678910Oxy
5 marks
Show answer
a) x = 0 and x = 3 b) draw y = x + 1; x ≈ -0.2 and x ≈ 4.2
13
  1. On the grid, draw the graph of x2 + y2 = 25
  2. On the same grid, draw the line y = x + 1
  3. Write down the coordinates of the points where the line meets the circle.
−6−5−4−3−2−1123456−6−5−4−3−2−1123456Oxy
4 marks
Show answer
a) circle with centre (0, 0) and radius 5 b) straight line through (0, 1), (3, 4) and (-4, -3) c) (3, 4) and (-4, -3)

Your score

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Every question here is original and written by Robinson Tuition. It follows the Key Stage 3 programme of study; Year 9 sheets end with extension questions for top sets.

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