(b) Draw the graph of \(y = x^3 + 4x^2\) for \(-5 \leqslant x \leqslant 1\).
[3]
(c) The equation \(x^3 + 4x^2 = k\), where \(k\) is an integer, has exactly one solution for \(-5 \leqslant x \leqslant 1\).
Find the greatest possible value of \(k\). [1]
Mark scheme (a)
Answer
Marks
Part marks and guidance
3
1
Mark scheme (b)
Answer
Marks
Part marks and guidance
Correct curve
3
B2FT for 7 or 8 correct plots or B1FT for 5 or 6 correct plots
Use overlay as a guide Mark curve first accuracy ± 1mm, ½ small sq Condone slight feathering Condone ruled segment between \(x = -5\) and \(x = -4.5\) only If curve incorrect then mark plots accuracy ± 1mm If no plot, curve implies plot