1MA0 Higher June 2015 Paper 2 Q28

(a) On the grid, construct the graph of \(x^2 + y^2 = 16\)

(2)

(b) Find estimates for the solutions of the simultaneous equations \[\begin{aligned} x^2 + y^2 &= 16 \\ y &= 2x + 1 \end{aligned}\] (3)

Mark scheme (a)

Answer	Mark	Notes
Circle drawn	2	B2 fully correct circle drawn (B1 for circle drawn with centre (0,0) or circle drawn with radius 4) OR M1 at least 5 correct points calculated and plotted A1 fully correct circle drawn

Mark scheme (b)

Answer	Mark	Notes
\(x = 1.4\), \(y = 3.8\) \(x = -2.2\), \(y = -3.4\)	3	M1 for \(y = 2x + 1\) drawn or for elimination of one variable A1 for one correct pair of values given or for \(x = 1.4, -2.2\) (\(\pm 0.2\)) or ft from graph provided 2 marks in (a) A1 for second correct pair of values given (\(\pm 0.2\)) or ft from graph provided 2 marks in (a)