15 22.5 4 P1 for (x2 30x) – P1 for process to complete the square, e.g. ((x 15)2 225) – – P1 for or substitution of = 15 x A1 cao OR P1 for 3x = 0 x2 – P1 for = 0 and = 30 x x P1 for substitution of = 15 x A1 cao 16 (a) Evaluation 1 C1 for correct evaluation of method seen, e.g. should have used instead of 16 (b) Evaluation 1 C1 for correct evaluation of result shown, e.g. the constant term should be not +6 or complete simplified expansion −6
15 22.5 4 P1 for (x2 – 30x) P1 for process to complete the square, e.g. ((x – 15)2 – 225) P1 for or substitution of x = 15 A1 cao OR P1 for x2 – 3x = 0 P1 for x = 0 and x = 30 P1 for substitution of x = 15 A1 cao 16 (a) Evaluation 1 C1 for correct evaluation of method seen, e.g. should have used instead of 16 (b) Evaluation 1 C1 for correct evaluation of result shown, e.g. the constant term should be −6 not +6 or complete simplified expansion
17745_08b_mock_papers_set_1_-_paper_1h_mark_scheme.docx