OCR MEI Further Numerical Methods 2023 June — Question 3 6 marks

Exam BoardOCR MEI
ModuleFurther Numerical Methods (Further Numerical Methods)
Year2023
SessionJune
Marks6
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicNumerical integration
TypeTrapezium rule applied to real-world data
DifficultyStandard +0.3 This is a straightforward application of standard numerical differentiation formulas (forward and central difference) with given tabulated values. Parts (a) and (b) require simple substitution into formulas, part (c) is a geometric interpretation, and part (d) tests basic understanding that central difference is generally more accurate. This is routine bookwork for Further Maths numerical methods with no problem-solving or novel insight required, making it slightly easier than average.
Spec1.09f Trapezium rule: numerical integration

3 The diagram shows the graph of \(y = f ( x )\) for values of \(x\) from 1 to 3.5. \includegraphics[max width=\textwidth, alt={}, center]{4023e87c-34b1-4abd-9acc-ede5e4d68c7f-03_945_1248_312_244} The table shows some values of \(x\) and the associated values of \(y\).
\(x\)1.522.5
\(y\)1.6821372.0943952.318559
  1. Use the forward difference method to calculate an approximation to \(\frac { \mathrm { dy } } { \mathrm { dx } }\) at \(x = 2\).
  2. Use the central difference method to calculate an approximation to \(\frac { \mathrm { dy } } { \mathrm { dx } }\) at \(x = 2\).
  3. On the copy of the diagram in the Printed Answer Booklet, show how the central difference method gives the approximation to \(\frac { \mathrm { dy } } { \mathrm { dx } }\) at \(x = 2\) which was found in part (b).
  4. Explain whether your answer to part (a) or your answer to part (b) is likely to give a better approximation to \(\frac { \mathrm { dy } } { \mathrm { dx } }\) at \(x = 2\).

Question 3:
AnswerMarks Guidance
3(a) oe soi
2.318559−2.094395
0.448328 isw or 0.44833 isw
AnswerMarks
2.5−2M1
A11.1
1.1allow B2 for correct answer unsupported
[2]
AnswerMarks Guidance
3(b) oe soi
2.318559−1.682137
0.636422 isw or 0.63642 isw
AnswerMarks
2.5−1.5M1
A11.1
1.1allow B2 for correct answer unsupported
[2]
AnswerMarks Guidance
3(c) chord joining point on curve where x = 1.5 to
point on curve where x = 2.5
and tangent to the curve at
x = 2 drawn;
[and gradient of chord identified as an
AnswerMarks Guidance
approximation to the gradient of the tangent]B1 1.1
[1]
AnswerMarks Guidance
3(d) central difference method is (usually) a
second order method whereas forward
difference is (usually) a first order method,
so answer to part (b) probably more accurate
or central difference method uses x-values
on both sides of 2 oe whereas forward
difference method uses a step in the positive
AnswerMarks Guidance
x-direction only oeB1 2.2b
must mention both methods
[1]
Question 3:
3 | (a) | oe soi
2.318559−2.094395
0.448328 isw or 0.44833 isw
2.5−2 | M1
A1 | 1.1
1.1 | allow B2 for correct answer unsupported
[2]
3 | (b) | oe soi
2.318559−1.682137
0.636422 isw or 0.63642 isw
2.5−1.5 | M1
A1 | 1.1
1.1 | allow B2 for correct answer unsupported
[2]
3 | (c) | chord joining point on curve where x = 1.5 to
point on curve where x = 2.5
and tangent to the curve at
x = 2 drawn;
[and gradient of chord identified as an
approximation to the gradient of the tangent] | B1 | 1.1
[1]
3 | (d) | central difference method is (usually) a
second order method whereas forward
difference is (usually) a first order method,
so answer to part (b) probably more accurate
or central difference method uses x-values
on both sides of 2 oe whereas forward
difference method uses a step in the positive
x-direction only oe | B1 | 2.2b | must mention both methods
must mention both methods
[1]
3 The diagram shows the graph of $y = f ( x )$ for values of $x$ from 1 to 3.5.\\
\includegraphics[max width=\textwidth, alt={}, center]{4023e87c-34b1-4abd-9acc-ede5e4d68c7f-03_945_1248_312_244}

The table shows some values of $x$ and the associated values of $y$.

\begin{center}
\begin{tabular}{ | c | c | c | c | }
\hline
$x$ & 1.5 & 2 & 2.5 \\
\hline
$y$ & 1.682137 & 2.094395 & 2.318559 \\
\hline
\end{tabular}
\end{center}
\begin{enumerate}[label=(\alph*)]
\item Use the forward difference method to calculate an approximation to $\frac { \mathrm { dy } } { \mathrm { dx } }$ at $x = 2$.
\item Use the central difference method to calculate an approximation to $\frac { \mathrm { dy } } { \mathrm { dx } }$ at $x = 2$.
\item On the copy of the diagram in the Printed Answer Booklet, show how the central difference method gives the approximation to $\frac { \mathrm { dy } } { \mathrm { dx } }$ at $x = 2$ which was found in part (b).
\item Explain whether your answer to part (a) or your answer to part (b) is likely to give a better approximation to $\frac { \mathrm { dy } } { \mathrm { dx } }$ at $x = 2$.
\end{enumerate}

\hfill \mbox{\textit{OCR MEI Further Numerical Methods 2023 Q3 [6]}}