OCR C2 2005 June — Question 3 7 marks

Exam BoardOCR
ModuleC2 (Core Mathematics 2)
Year2005
SessionJune
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicIndefinite & Definite Integrals
TypeIntegration with algebraic manipulation
DifficultyModerate -0.8 This is a straightforward C2 integration question with two routine parts: (i) requires expanding brackets then integrating a polynomial (standard technique), and (ii) is direct integration of x^(-1/2) with simple limits. Both parts are textbook exercises requiring only recall of basic integration rules with minimal problem-solving.
Spec1.08b Integrate x^n: where n != -1 and sums

3
  1. Find \(\int ( 2 x + 1 ) ( x + 3 ) \mathrm { d } x\).
  2. Evaluate \(\int _ { 0 } ^ { 9 } \frac { 1 } { \sqrt { x } } \mathrm {~d} x\).

AnswerMarks Guidance
(i) \(\int(2x^2 + 7x + 3) \, dx\)M1 For expanding and integration attempt
\(= \frac{2}{3}x^3 + \frac{7}{2}x^2 + 3x + c\)A1, A1, B1 For at least one term correct; For all three terms correct; For addition of arbitrary constant, and no \(\int\) or \(dx\)
(ii) \(\int 2x \, dx = 6\)M1, M1, A1 For integral of the form \(kx^3\); For evaluating at least \(F(9)\), following attempt at integration; For final answer of 6 only
**(i)** $\int(2x^2 + 7x + 3) \, dx$ | M1 | For expanding and integration attempt

$= \frac{2}{3}x^3 + \frac{7}{2}x^2 + 3x + c$ | A1, A1, B1 | For at least one term correct; For all three terms correct; For addition of arbitrary constant, and no $\int$ or $dx$

**(ii)** $\int 2x \, dx = 6$ | M1, M1, A1 | For integral of the form $kx^3$; For evaluating at least $F(9)$, following attempt at integration; For final answer of 6 only

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3 (i) Find $\int ( 2 x + 1 ) ( x + 3 ) \mathrm { d } x$.\\
(ii) Evaluate $\int _ { 0 } ^ { 9 } \frac { 1 } { \sqrt { x } } \mathrm {~d} x$.

\hfill \mbox{\textit{OCR C2 2005 Q3 [7]}}