(c) (75) = 150(75) 0.6(75)2 I – (M1) = $7875 (A1) Selling per machine = (M1) = $105 (A1) 4 Notes: If P(75) or C(75) used, award M0 A0 but ft with candidate’s value to the selling price. (d) = 0 or (x 20)(130 = 0. P(x) x) – – (M1) = 20 (130 need not be mentioned) x (A2) Smallest number must be 21. (A1) 4 Notes: If no working shown: Award (G2) if answer is 20, x > 20 or x = 20, Award (G3) if answer is 21 or x = 21. A sketch of the function showing the intercepts receives (M1) with (A2) or (A3) for separate indication of answer 20 or 21 respectively. If brackets are expanded and quadratic formula is used, the (M1) should be awarded only for correct expansion and correct substitution into the formula. [12] 10. (a) (A1) (C1) y Note: The equation = 5 is not required (b) (i) = (A1) x –2 = 4 (A1) x (C2)
(c) I (75) = 150(75) – 0.6(75)2 (M1) = $7875 (A1) Selling per machine = (M1) = $105 (A1) 4 Notes: If P(75) or C(75) used, award M0 A0 but ft with candidate’s value to the selling price. (d) P(x) = 0 or (x – 20)(130 – x) = 0. (M1) x = 20 (130 need not be mentioned) (A2) Smallest number must be 21. (A1) 4 Notes: If no working shown: Award (G2) if answer is 20, x > 20 or x = 20, Award (G3) if answer is 21 or x = 21. A sketch of the function showing the intercepts receives (M1) with (A2) or (A3) for separate indication of answer 20 or 21 respectively. If brackets are expanded and quadratic formula is used, the (M1) should be awarded only for correct expansion and correct substitution into the formula. [12] 10. (a) (A1) (C1) Note: The equation y = 5 is not required (b) (i) x = –2 (A1) x = 4 (A1) (C2)
ms_1_review_package_for_quadratic_functions2.docx