Graphs 6
4 marks · HardThe function is to be plotted for .
Complete the table below by calculating the value of y for each value of x.
| x | y |
|---|---|
| -2 | |
| -1 | |
| 0 | |
| 1 | |
| 2 |
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(-2) -8
(-1) 3
(0) 0
(1) -3
(2) 0
Common mistakes: Errors in cube or sign; Substituting incorrectly
Show mark scheme and worked solution
Marking points
M1 · 1 mark · Substitutes x = -2 into y = x^3 - 4x correctly.
M1 · 1 mark · Substitutes x = -1 into y = x^3 - 4x correctly.
M1 · 1 mark · Substitutes x = 1 into y = x^3 - 4x correctly.
A1 · 1 mark · All answers correct in the table.
Worked solution
Substitute the given values of x into y = x^3 - 4x:
| x | y |
|---|---|
| -2 | (-2)^3 - 4(-2) = -8 + 8 = 0 |
| -1 | (-1)^3 - 4(-1) = -1 + 4 = 3 |
| 0 | 0^3 - 4×0 = 0 |
| 1 | 1^3 - 4×1 = 1 - 4 = -3 |
| 2 | 2^3 - 4×2 = 8 - 8 = 0 |
Correct table: x | y -2 | 0 -1 | 3 0 | 0 1 | -3 2 | 0