OCR MEI C1 2011 June — Question 6 3 marks

Exam BoardOCR MEI
ModuleC1 (Core Mathematics 1)
Year2011
SessionJune
Marks3
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicCurve Sketching
TypeSketch then expand or factorise
DifficultyEasy -1.2 This is a straightforward algebraic expansion requiring multiplication of three linear factors with no conceptual difficulty. It's purely procedural—expand two brackets first, then multiply by the third—and is easier than average A-level content, though the three factors make it slightly less trivial than a two-bracket expansion.
Spec1.02j Manipulate polynomials: expanding, factorising, division, factor theorem

Expand \((2x + 5)(x - 1)(x + 3)\), simplifying your answer. [3]

AnswerMarks Guidance
\(2x^3 + 9x^2 + 4x - 15\)3 as final answer; ignore '= 0'; B2 for 3 correct terms of answer seen or for an 8-term or 6 term expansion with at most one error; or M1 for correct quadratic expansion of one pair of brackets; or SC1 for a quadratic expansion with one error then a good attempt to multiply by the remaining bracket
$2x^3 + 9x^2 + 4x - 15$ | 3 | as final answer; ignore '= 0'; B2 for 3 correct terms of answer seen or for an 8-term or 6 term expansion with at most one error; or M1 for correct quadratic expansion of one pair of brackets; or SC1 for a quadratic expansion with one error then a good attempt to multiply by the remaining bracket | correct 8-term expansion: $2x^3 + 6x^2 - 2x^2 + 5x^2 - 6x + 15x - 5x - 15$ correct 6-term expansions: $2x^3 + 4x^2 + 5x^2 - 6x + 10x - 15$ / $2x^3 + 6x^2 + 3x^2 + 9x - 5x - 15$ / $2x^3 + 11x^2 - 2x^2 + 15x - 11x - 15$; for M1, need not be simplified; ie SC1 for knowing what to do and making a reasonable attempt, even if an error at an early stage means more marks not available
Expand $(2x + 5)(x - 1)(x + 3)$, simplifying your answer. [3]

\hfill \mbox{\textit{OCR MEI C1 2011 Q6 [3]}}