| Exam Board | Edexcel |
|---|---|
| Module | P2 (Pure Mathematics 2) |
| Year | 2023 |
| Session | June |
| Marks | 3 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Numerical integration |
| Type | Apply trapezium rule to given table |
| Difficulty | Easy -1.3 This is a straightforward application of the trapezium rule formula with all values provided in a table. It requires only direct substitution into a standard formula with no problem-solving, making it significantly easier than average and purely procedural. |
| Spec | 1.09f Trapezium rule: numerical integration |
| \(x\) | 4.0 | 4.2 | 4.4 | 4.6 | 4.8 | 5.0 |
| \(y\) | 9.2 | 8.4556 | 3.8512 | 5.0342 | 7.8297 | 8.6 |
| Answer | Marks | Guidance |
|---|---|---|
| Answer/Working | Mark | Guidance |
| \(h = 0.2\) | B1 | o.e. including \(\frac{5-4}{5}\); seen or implied by sight of e.g. \(\frac{0.2}{2}\) or \(\frac{1}{10}\) in front of bracket. May be implied by correct answer if no incorrect working. \(h = -0.2\) is B0 |
| \(\frac{1}{2} \times \text{"0.2"} \times [9.2 + 8.6 + 2(8.4556 + 3.8512 + 5.0342 + 7.8297)]\) | M1 | Correct application of trapezium rule with their \(h\). Correct inner bracket structure \(9.2 + 8.6 + 2(8.4556 + 3.8512 + 5.0342 + 7.8297)\), condoning slips copying values or omission of final brackets on rhs |
| \(6.814\) | A1 | awrt 6.814 isw once correct answer seen. Correct answer with no working scores B1M1A1. If \(h = -0.2\) used, maximum is B0M1A0. A mark cannot be awarded without both B1M1 |
| Answer | Marks | Guidance |
|---|---|---|
| Answer/Working | Mark | Guidance |
| \(f\!\left(\frac{3}{2}\right) = 4\!\left(\frac{3}{2}\right)^3 - 8\!\left(\frac{3}{2}\right)^2 + 5\!\left(\frac{3}{2}\right) + a = 0 \Rightarrow a = \ldots\) | M1 | Substitutes \(x = \frac{3}{2}\) into expression, sets equal to 0 and rearranges to find \(a\). Substituting \(x = -\frac{3}{2}\) is M0. Attempting via long division scores M0 |
| \(\Rightarrow \frac{27}{2} - 18 + \frac{15}{2} + a = 0 \Rightarrow a = -3\) | A1* | \(a = -3\) achieved with no errors seen including omission of brackets. Must see \(x = \frac{3}{2}\), at least one intermediate step, and "\(= 0\)" somewhere before the answer |
| Answer | Marks | Guidance |
|---|---|---|
| Answer/Working | Mark | Guidance |
| Attempts to find quadratic factor of \(4x^3 - 8x^2 + 5x - 3\) using \(2x-3\) as factor, obtaining \(2x^2 \pm x \pm \ldots\) | M1 | Score for \(2x^2 \pm x \pm \ldots\) if algebraic division used, or \(2x^2 \pm \ldots x \pm 1\) if equating coefficients/inspection used |
| \(2x^2 - x + 1\) (for \(2x-3\) as linear factor) | A1 | Or \(4x^2 - 2x + 2\) for \(x - \frac{3}{2}\) as linear factor |
| \((-1)^2 - 4 \times 2 \times 1 = -7 < 0\) | dM1 | Dependent on previous M. Attempts to show quadratic factor has no real roots via \(b^2 - 4ac\), solving quadratic formula, or completing the square |
| \(\Rightarrow\) no real roots so \(x = \frac{3}{2}\) is the only real root | A1* | Requires correct factorisation of cubic, correct calculation for quadratic, reason and conclusion. Must reference root \(x = \frac{3}{2}\) |
| Answer | Marks | Guidance |
|---|---|---|
| Answer/Working | Mark | Guidance |
| \(r = \sqrt{(8-2)^2 + (-3-5)^2} = 10\) | M1 | Attempts to find radius; values embedded in expression finding difference in \(x\) and \(y\) coordinates |
| \((r =)\ 10\) | A1 | Ignore units. \(\pm 10\) is A0. Do not accept \(\sqrt{100}\). isw once correct answer seen |
| \((x-2)^2 + (y-5)^2 = 100\) | A1ft | o.e. e.g. \((x-2)^2+(y-5)^2 = \text{"10}^2\text{"}\). Follow through on their positive single value of \(r\) |
| Answer | Marks | Guidance |
|---|---|---|
| Answer/Working | Mark | Guidance |
| Gradient between centre and \(P = -\frac{4}{3}\) | B1 | May be implied by their gradient of the tangent |
| Perpendicular gradient \(= \frac{3}{4}\) | M1 | Attempts negative reciprocal of their gradient; may be embedded in equation of tangent |
| \(y + 3 = \frac{3}{4}(x - 8)\) | M1 | Attempts equation of tangent at \(P\) using changed gradient and point \((8, -3)\). If \(y=mx+c\) used must proceed to \(c = \ldots\) |
| \(3x - 4y - 36 = 0\) | A1 | o.e. provided all coefficients are integers and all terms on one side. isw once correct equation seen |
# Question 1:
| Answer/Working | Mark | Guidance |
|---|---|---|
| $h = 0.2$ | B1 | o.e. including $\frac{5-4}{5}$; seen or implied by sight of e.g. $\frac{0.2}{2}$ or $\frac{1}{10}$ in front of bracket. May be implied by correct answer if no incorrect working. $h = -0.2$ is B0 |
| $\frac{1}{2} \times \text{"0.2"} \times [9.2 + 8.6 + 2(8.4556 + 3.8512 + 5.0342 + 7.8297)]$ | M1 | Correct application of trapezium rule with their $h$. Correct inner bracket structure $9.2 + 8.6 + 2(8.4556 + 3.8512 + 5.0342 + 7.8297)$, condoning slips copying values or omission of final brackets on rhs |
| $6.814$ | A1 | awrt 6.814 isw once correct answer seen. Correct answer with no working scores B1M1A1. If $h = -0.2$ used, maximum is B0M1A0. A mark cannot be awarded without both B1M1 |
---
# Question 2a:
| Answer/Working | Mark | Guidance |
|---|---|---|
| $f\!\left(\frac{3}{2}\right) = 4\!\left(\frac{3}{2}\right)^3 - 8\!\left(\frac{3}{2}\right)^2 + 5\!\left(\frac{3}{2}\right) + a = 0 \Rightarrow a = \ldots$ | M1 | Substitutes $x = \frac{3}{2}$ into expression, sets equal to 0 and rearranges to find $a$. Substituting $x = -\frac{3}{2}$ is M0. Attempting via long division scores M0 |
| $\Rightarrow \frac{27}{2} - 18 + \frac{15}{2} + a = 0 \Rightarrow a = -3$ | A1* | $a = -3$ achieved with no errors seen including omission of brackets. Must see $x = \frac{3}{2}$, at least one intermediate step, and "$= 0$" somewhere before the answer |
# Question 2b:
| Answer/Working | Mark | Guidance |
|---|---|---|
| Attempts to find quadratic factor of $4x^3 - 8x^2 + 5x - 3$ using $2x-3$ as factor, obtaining $2x^2 \pm x \pm \ldots$ | M1 | Score for $2x^2 \pm x \pm \ldots$ if algebraic division used, or $2x^2 \pm \ldots x \pm 1$ if equating coefficients/inspection used |
| $2x^2 - x + 1$ (for $2x-3$ as linear factor) | A1 | Or $4x^2 - 2x + 2$ for $x - \frac{3}{2}$ as linear factor |
| $(-1)^2 - 4 \times 2 \times 1 = -7 < 0$ | dM1 | Dependent on previous M. Attempts to show quadratic factor has no real roots via $b^2 - 4ac$, solving quadratic formula, or completing the square |
| $\Rightarrow$ no real roots so $x = \frac{3}{2}$ is the only real root | A1* | Requires correct factorisation of cubic, correct calculation for quadratic, reason and conclusion. Must reference root $x = \frac{3}{2}$ |
---
# Question 3a(i) and (ii):
| Answer/Working | Mark | Guidance |
|---|---|---|
| $r = \sqrt{(8-2)^2 + (-3-5)^2} = 10$ | M1 | Attempts to find radius; values embedded in expression finding difference in $x$ and $y$ coordinates |
| $(r =)\ 10$ | A1 | Ignore units. $\pm 10$ is A0. Do not accept $\sqrt{100}$. isw once correct answer seen |
| $(x-2)^2 + (y-5)^2 = 100$ | A1ft | o.e. e.g. $(x-2)^2+(y-5)^2 = \text{"10}^2\text{"}$. Follow through on their positive single value of $r$ |
# Question 3b:
| Answer/Working | Mark | Guidance |
|---|---|---|
| Gradient between centre and $P = -\frac{4}{3}$ | B1 | May be implied by their gradient of the tangent |
| Perpendicular gradient $= \frac{3}{4}$ | M1 | Attempts negative reciprocal of their gradient; may be embedded in equation of tangent |
| $y + 3 = \frac{3}{4}(x - 8)$ | M1 | Attempts equation of tangent at $P$ using changed gradient and point $(8, -3)$. If $y=mx+c$ used must proceed to $c = \ldots$ |
| $3x - 4y - 36 = 0$ | A1 | o.e. provided all coefficients are integers and all terms on one side. isw once correct equation seen |
\begin{enumerate}
\item The continuous curve $C$ has equation $y = \mathrm { f } ( x )$.
\end{enumerate}
A table of values of $x$ and $y$ for $y = \mathrm { f } ( x )$ is shown below.
\begin{center}
\begin{tabular}{ | c | c | c | c | c | c | c | }
\hline
$x$ & 4.0 & 4.2 & 4.4 & 4.6 & 4.8 & 5.0 \\
\hline
$y$ & 9.2 & 8.4556 & 3.8512 & 5.0342 & 7.8297 & 8.6 \\
\hline
\end{tabular}
\end{center}
Use the trapezium rule with all the values of $y$ in the table to find an approximation for
$$\int _ { 4 } ^ { 5 } f ( x ) d x$$
giving your answer to 3 decimal places.
\hfill \mbox{\textit{Edexcel P2 2023 Q1 [3]}}