Edexcel C4 2010 June — Question 1 8 marks

Exam BoardEdexcel
ModuleC4 (Core Mathematics 4)
Year2010
SessionJune
Marks8
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicNumerical integration
TypeCompare two trapezium rule estimates
DifficultyModerate -0.3 This is a straightforward trapezium rule application requiring table completion by substitution, then two standard calculations with different strip numbers. The function evaluation is routine (calculator work), and the trapezium rule formula is a standard C4 technique with no conceptual challenges or problem-solving required. Slightly easier than average due to its purely procedural nature.
Spec1.09f Trapezium rule: numerical integration

1. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{280ae2a5-7344-4ba3-907f-235fba3fd5b3-02_684_767_274_589} \captionsetup{labelformat=empty} \caption{Figure 1}
\end{figure} Figure 1 shows part of the curve with equation \(y = \sqrt { } \left( 0.75 + \cos ^ { 2 } x \right)\). The finite region \(R\), shown shaded in Figure 1, is bounded by the curve, the \(y\)-axis, the \(x\)-axis and the line with equation \(x = \frac { \pi } { 3 }\).
  1. Complete the table with values of \(y\) corresponding to \(x = \frac { \pi } { 6 }\) and \(x = \frac { \pi } { 4 }\).
    \(x\)0\(\frac { \pi } { 12 }\)\(\frac { \pi } { 6 }\)\(\frac { \pi } { 4 }\)\(\frac { \pi } { 3 }\)
    \(y\)1.32291.29731
  2. Use the trapezium rule
    1. with the values of \(y\) at \(x = 0 , x = \frac { \pi } { 6 }\) and \(x = \frac { \pi } { 3 }\) to find an estimate of the area of \(R\). Give your answer to 3 decimal places.
    2. with the values of \(y\) at \(x = 0 , x = \frac { \pi } { 12 } , x = \frac { \pi } { 6 } , x = \frac { \pi } { 4 }\) and \(x = \frac { \pi } { 3 }\) to find a further estimate of the area of \(R\). Give your answer to 3 decimal places.
      (6) \section*{LU}

AnswerMarks Guidance
(a)\(y\left(\frac{\pi}{6}\right) \approx 1.2247\), \(y\left(\frac{\pi}{4}\right) = 1.1180\) B1 B1
\(I \approx \frac{\pi}{12}(1.3229 + 2 \times 1.2247 + 1) \approx 1.249\)B1 M1 B1 for \(\frac{\pi}{12}\), cao
(b)(i)\(I \approx \frac{\pi}{12}(1.3229 + 2 \times 1.2247 + 1) \approx 1.249\) B1 M1
(b)(ii)\(I \approx \frac{\pi}{24}(1.3229 + 2 \times (1.2973 + 1.2247 + 1.1180) + 1) \approx 1.257\) B1 M1
(a) | $y\left(\frac{\pi}{6}\right) \approx 1.2247$, $y\left(\frac{\pi}{4}\right) = 1.1180$ | B1 B1 | accept awrt 4 d.p. |
| $I \approx \frac{\pi}{12}(1.3229 + 2 \times 1.2247 + 1) \approx 1.249$ | B1 M1 | B1 for $\frac{\pi}{12}$, cao |

(b)(i) | $I \approx \frac{\pi}{12}(1.3229 + 2 \times 1.2247 + 1) \approx 1.249$ | B1 M1 | B1 for $\frac{\pi}{12}$, cao |

(b)(ii) | $I \approx \frac{\pi}{24}(1.3229 + 2 \times (1.2973 + 1.2247 + 1.1180) + 1) \approx 1.257$ | B1 M1 | B1 for $\frac{\pi}{24}$, cao |

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1.

\begin{figure}[h]
\begin{center}
  \includegraphics[alt={},max width=\textwidth]{280ae2a5-7344-4ba3-907f-235fba3fd5b3-02_684_767_274_589}
\captionsetup{labelformat=empty}
\caption{Figure 1}
\end{center}
\end{figure}

Figure 1 shows part of the curve with equation $y = \sqrt { } \left( 0.75 + \cos ^ { 2 } x \right)$. The finite region $R$, shown shaded in Figure 1, is bounded by the curve, the $y$-axis, the $x$-axis and the line with equation $x = \frac { \pi } { 3 }$.
\begin{enumerate}[label=(\alph*)]
\item Complete the table with values of $y$ corresponding to $x = \frac { \pi } { 6 }$ and $x = \frac { \pi } { 4 }$.

\begin{center}
\begin{tabular}{ | c | c | c | c | c | c | }
\hline
$x$ & 0 & $\frac { \pi } { 12 }$ & $\frac { \pi } { 6 }$ & $\frac { \pi } { 4 }$ & $\frac { \pi } { 3 }$ \\
\hline
$y$ & 1.3229 & 1.2973 &  &  & 1 \\
\hline
\end{tabular}
\end{center}
\item Use the trapezium rule
\begin{enumerate}[label=(\roman*)]
\item with the values of $y$ at $x = 0 , x = \frac { \pi } { 6 }$ and $x = \frac { \pi } { 3 }$ to find an estimate of the area of $R$. Give your answer to 3 decimal places.
\item with the values of $y$ at $x = 0 , x = \frac { \pi } { 12 } , x = \frac { \pi } { 6 } , x = \frac { \pi } { 4 }$ and $x = \frac { \pi } { 3 }$ to find a further estimate of the area of $R$. Give your answer to 3 decimal places.\\
(6)

\section*{LU}
\end{enumerate}\end{enumerate}

\hfill \mbox{\textit{Edexcel C4 2010 Q1 [8]}}