2 = 4) e.g. y – –4(x – = + 18 AG N0 y –4x (b) recognition that = 0 at A (M1) y + 18 = 0 e.g. –4x = A1 N2 x (c) splitting into two appropriate parts (areas and/or integrals) (M1) correct expression for area of A2 N3 R area of = (triangle) e.g. R Note: A1 if dx is missing. (d) correct expression for the volume from = 0 to = 4 (A1) x x = e.g. V = A1 V = (A1) V = 8π A1 V finding the volume from = 4 to = 4.5 x x EITHER recognizing a cone (M1) = e.g. V πr2h = (A1) V = A1 total volume is 8π + A1 N4 OR = (M1) V = = A1 = A1 total volume is 8π + A1 N4 [17] 9. METHOD 1 correct expression for second side, area = 525 (A1) let AB = AD = e.g. x, attempt to set up cost function using $3 for three sides and $11 for one side (M1) 3(AD + BC + CD) + 11AB e.g. correct expression for cost A2 e.g. EITHER sketch of cost function (M1) identifying minimum (A1) marking point on graph, = 15 e.g. x minimum cost is 420 (dollars) A1 N4 OR
e.g. y – 2 = –4(x – 4) y = –4x + 18 AG N0 (b) recognition that y = 0 at A (M1) e.g. –4x + 18 = 0 x = A1 N2 (c) splitting into two appropriate parts (areas and/or integrals) (M1) correct expression for area of R A2 N3 e.g. area of R = (triangle) Note: A1 if dx is missing. (d) correct expression for the volume from x = 0 to x = 4 (A1) e.g. V = V = A1 V = (A1) V = 8π A1 finding the volume from x = 4 to x = 4.5 EITHER recognizing a cone (M1) e.g. V = πr2h V = (A1) = A1 total volume is 8π + A1 N4 OR V = (M1) = = A1 = A1 total volume is 8π + A1 N4 [17] 9. METHOD 1 correct expression for second side, area = 525 (A1) e.g. let AB = x, AD = attempt to set up cost function using $3 for three sides and $11 for one side (M1) e.g. 3(AD + BC + CD) + 11AB correct expression for cost A2 e.g. EITHER sketch of cost function (M1) identifying minimum (A1) e.g. marking point on graph, x = 15 minimum cost is 420 (dollars) A1 N4 OR
semester_1_review.docx