10 Here is a table of values for \(y = x^2 - x - 8\).
\(x\)
-4
-3
-2
-1
0
1
2
3
4
\(y\)
12
4
-2
-6
-8
-8
-6
-2
4
(a) Draw the graph of \(y = x^2 - x - 8\) for \(-4 \leqslant x \leqslant 4\). [3]
(b) Write down the equation of the line of symmetry of the graph. [1]
(c) Use the graph to solve the equation \(x^2 - x - 8 = 0\). Give your answers to 1 decimal place. [2]
Mark scheme (a)
Answer
Marks
Part marks and guidance
correct curve within tolerance
3
B2 for 8 points accurately plotted or B1 for 5 points accurately plotted
tolerance \(\pm\frac{1}{2}\) small square radially for curve and points, some daylight between \(y = -8\) and curve, condone a wobbly curve and slight feathering or tram lines in no more than 3 sections but no ruled lines and no dashed lines
Mark scheme (b)
Answer
Marks
Part marks and guidance
\(x = 0.5\) oe
1
Mark scheme (c)
Answer
Marks
Part marks and guidance
–2.3 or –2.4 3.3 or 3.4
2
B1 for either answer SC1 for an answer to more than 1 dp in each of –2.4 to –2.3 and 3.3 to 3.4
If 1 scored FTtheir curve for 2 marks or if 0 scored FTtheir curve for 1 or 2 marks or for SC1
tolerance \(\pm\frac{1}{2}\) small square radially
