OCR C2 — Question 7 9 marks

Exam BoardOCR
ModuleC2 (Core Mathematics 2)
Marks9
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicStandard Integrals and Reverse Chain Rule
TypeArea under curve using integration
DifficultyModerate -0.3 This is a straightforward C2 integration question requiring algebraic manipulation (splitting the fraction), basic integration of power functions, and finding a definite integral. While it has multiple parts, each step follows standard procedures with no novel insight required, making it slightly easier than average.
Spec1.08b Integrate x^n: where n != -1 and sums1.08e Area between curve and x-axis: using definite integrals

7. \includegraphics[max width=\textwidth, alt={}, center]{e5d62032-84ad-4e0b-9b72-ccfd8f4dbac8-3_499_721_248_552} The diagram shows part of the curve \(y = \mathrm { f } ( x )\) where \(\mathrm { f } ( x ) = \frac { 1 - 8 x ^ { 3 } } { x ^ { 2 } } , x \neq 0\).
  1. Solve the equation \(\mathrm { f } ( x ) = 0\).
  2. Find \(\int \mathrm { f } ( x ) \mathrm { d } x\).
  3. Find the area of the shaded region bounded by the curve \(y = \mathrm { f } ( x )\), the \(x\)-axis and the line \(x = 2\).

Question 7:
Part (i):
AnswerMarks
\(\frac{1-8x^3}{x^2} = 0 \Rightarrow 1 - 8x^3 = 0\)M1
\(x^3 = \frac{1}{8}\)M1
\(x = \frac{1}{2}\)A1
Part (ii):
\(f(x) = x^{-2} - 8x\)
\(\int f(x)\, dx = \int (x^{-2} - 8x)\, dx\)
AnswerMarks
\(= -x^{-1} - 4x^2 + c\)M1 A2
Part (iii):
AnswerMarks Guidance
\(= -[-x^{-1} - 4x^2]_{\frac{1}{2}}^{2}\)M1
\(= -\{(-\frac{1}{2} - 16) - (-2 - 1)\} = 13\frac{1}{2}\)M1 A1 (9)
# Question 7:

## Part (i):
$\frac{1-8x^3}{x^2} = 0 \Rightarrow 1 - 8x^3 = 0$ | M1 |
$x^3 = \frac{1}{8}$ | M1 |
$x = \frac{1}{2}$ | A1 |

## Part (ii):
$f(x) = x^{-2} - 8x$
$\int f(x)\, dx = \int (x^{-2} - 8x)\, dx$
$= -x^{-1} - 4x^2 + c$ | M1 A2 |

## Part (iii):
$= -[-x^{-1} - 4x^2]_{\frac{1}{2}}^{2}$ | M1 |
$= -\{(-\frac{1}{2} - 16) - (-2 - 1)\} = 13\frac{1}{2}$ | M1 A1 | **(9)**

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7.\\
\includegraphics[max width=\textwidth, alt={}, center]{e5d62032-84ad-4e0b-9b72-ccfd8f4dbac8-3_499_721_248_552}

The diagram shows part of the curve $y = \mathrm { f } ( x )$ where $\mathrm { f } ( x ) = \frac { 1 - 8 x ^ { 3 } } { x ^ { 2 } } , x \neq 0$.\\
(i) Solve the equation $\mathrm { f } ( x ) = 0$.\\
(ii) Find $\int \mathrm { f } ( x ) \mathrm { d } x$.\\
(iii) Find the area of the shaded region bounded by the curve $y = \mathrm { f } ( x )$, the $x$-axis and the line $x = 2$.\\

\hfill \mbox{\textit{OCR C2  Q7 [9]}}