Q4 [S marks] For different values of the parameter a, we get 170 different cubic curves of the family " 160 \\. 150. y =x2(ax). : 140 130 A number of members of this family are drawn at the right. 120} We will define the vertex of each curve to be the maximum 110 point of the curve on the interval x > 0. 100 i3 920 i~ 80 Your job is to find the equation of the curve that passes = through all the vertices. You may use calculus. | e 50 \\ 40 30. 20 55-4-3-2-10134 8- % 10 v 12