OCR FP2 2009 June — Question 1 5 marks

Exam BoardOCR
ModuleFP2 (Further Pure Mathematics 2)
Year2009
SessionJune
Marks5
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicNumerical integration
TypeRectangle bounds for definite integral
DifficultyModerate -0.3 This is a straightforward application of upper and lower Riemann sums using rectangles to bound an area. While it's FP2, the question requires only basic understanding of how rectangles approximate areas (using left/right endpoints for bounds) and simple calculator work to evaluate ln(cos x) at given points. The conceptual demand is minimal—standard textbook exercise with clear instructions and diagram.
Spec1.09f Trapezium rule: numerical integration

1 \includegraphics[max width=\textwidth, alt={}, center]{cf77e51a-1d3f-423a-be59-96ec60fbeb67-2_568_959_269_593} The diagram shows the curve with equation \(y = \ln ( \cos x )\), for \(0 \leqslant x \leqslant 1.5\). The region bounded by the curve, the \(x\)-axis and the line \(x = 1.5\) has area \(A\). The region is divided into five strips, each of width 0.3 .
  1. By considering the set of rectangles indicated in the diagram, find an upper bound for \(A\). Give the answer correct to 3 decimal places.
  2. By considering another set of five suitable rectangles, find a lower bound for \(A\). Give the answer correct to 3 decimal places.
  3. How could you reduce the difference between the upper and lower bounds for \(A\) ?

1\\
\includegraphics[max width=\textwidth, alt={}, center]{cf77e51a-1d3f-423a-be59-96ec60fbeb67-2_568_959_269_593}

The diagram shows the curve with equation $y = \ln ( \cos x )$, for $0 \leqslant x \leqslant 1.5$. The region bounded by the curve, the $x$-axis and the line $x = 1.5$ has area $A$. The region is divided into five strips, each of width 0.3 .\\
(i) By considering the set of rectangles indicated in the diagram, find an upper bound for $A$. Give the answer correct to 3 decimal places.\\
(ii) By considering another set of five suitable rectangles, find a lower bound for $A$. Give the answer correct to 3 decimal places.\\
(iii) How could you reduce the difference between the upper and lower bounds for $A$ ?

\hfill \mbox{\textit{OCR FP2 2009 Q1 [5]}}