CAIE P2 2003 June — Question 3 6 marks

Exam BoardCAIE
ModuleP2 (Pure Mathematics 2)
Year2003
SessionJune
Marks6
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicStandard Integrals and Reverse Chain Rule
TypeArea under curve using integration
DifficultyModerate -0.8 This is a straightforward integration question requiring only the standard integral of e^(2x) and solving a simple logarithmic equation. Part (i) is routine application of integration with substitution or recognition of the reverse chain rule, and part (ii) involves basic algebraic manipulation of exponentials and logarithms. Both parts are below average difficulty for A-level, being standard textbook exercises with no problem-solving insight required.
Spec1.08c Integrate e^(kx), 1/x, sin(kx), cos(kx)1.08d Evaluate definite integrals: between limits

3 \includegraphics[max width=\textwidth, alt={}, center]{a31a4b4e-83a6-47d9-9679-3471b3da1b6e-2_488_664_863_737} The diagram shows the curve \(y = \mathrm { e } ^ { 2 x }\). The shaded region \(R\) is bounded by the curve and by the lines \(x = 0 , y = 0\) and \(x = p\).
  1. Find, in terms of \(p\), the area of \(R\).
  2. Hence calculate the value of \(p\) for which the area of \(R\) is equal to 5 . Give your answer correct to 2 significant figures.

Question 3(i):
AnswerMarks Guidance
Answer/WorkingMark Guidance
State or imply indefinite integral of \(e^{2x}\) is \(\frac{1}{2}e^{2x}\), or equivalentB1
Substitute correct limits correctlyM1
Obtain answer \(R = \frac{1}{2}e^{2p} - \frac{1}{2}\), or equivalentA1
Total: [3]
Question 3(ii):
AnswerMarks Guidance
Answer/WorkingMark Guidance
Substitute \(R = 5\) and use logarithmic method to obtain an equation in \(2p\)M1*
Solve for \(p\)M1 (dep*)
Obtain answer \(p = 1.2\) \((1.1989...)\)A1
Total: [3]
# Question 3(i):

| Answer/Working | Mark | Guidance |
|---|---|---|
| State or imply indefinite integral of $e^{2x}$ is $\frac{1}{2}e^{2x}$, or equivalent | B1 | |
| Substitute correct limits correctly | M1 | |
| Obtain answer $R = \frac{1}{2}e^{2p} - \frac{1}{2}$, or equivalent | A1 | |

**Total: [3]**

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# Question 3(ii):

| Answer/Working | Mark | Guidance |
|---|---|---|
| Substitute $R = 5$ and use logarithmic method to obtain an equation in $2p$ | M1* | |
| Solve for $p$ | M1 (dep*) | |
| Obtain answer $p = 1.2$ $(1.1989...)$ | A1 | |

**Total: [3]**

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3\\
\includegraphics[max width=\textwidth, alt={}, center]{a31a4b4e-83a6-47d9-9679-3471b3da1b6e-2_488_664_863_737}

The diagram shows the curve $y = \mathrm { e } ^ { 2 x }$. The shaded region $R$ is bounded by the curve and by the lines $x = 0 , y = 0$ and $x = p$.\\
(i) Find, in terms of $p$, the area of $R$.\\
(ii) Hence calculate the value of $p$ for which the area of $R$ is equal to 5 . Give your answer correct to 2 significant figures.

\hfill \mbox{\textit{CAIE P2 2003 Q3 [6]}}