Edexcel C3 Specimen — Question 5 12 marks

Exam BoardEdexcel
ModuleC3 (Core Mathematics 3)
SessionSpecimen
Marks12
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicModulus function
TypeTransformations of modulus graphs from given f(x) sketch
DifficultyModerate -0.3 This is a standard C3 question testing routine transformations of graphs (modulus and combined stretch/scale) and basic logarithm/differentiation skills. Part (a) requires applying well-practiced transformation rules, while parts (b)-(d) involve straightforward substitution, solving ln equations, and finding a tangent—all standard textbook exercises with no novel problem-solving required. Slightly easier than average due to the mechanical nature of all parts.
Spec1.02w Graph transformations: simple transformations of f(x)1.06d Natural logarithm: ln(x) function and properties1.07l Derivative of ln(x): and related functions

5. \begin{figure}[h]
\captionsetup{labelformat=empty} \caption{Figure 1} \includegraphics[alt={},max width=\textwidth]{937edb48-ef4c-4974-a571-60b0fded841b-3_394_680_982_680}
\end{figure} Figure 1 shows part of the curve with equation \(y = \mathrm { f } ( x ) , x \in \mathbb { R }\). The curve meets the \(x\)-axis at \(P ( p , 0 )\) and meets the \(y\)-axis at \(Q ( 0 , q )\).
  1. On separate diagrams, sketch the curve with equation
    1. \(y = | \mathrm { f } ( x ) |\),
    2. \(y = 3 \mathrm { f } \left( \frac { 1 } { 2 } x \right)\). In each case show, in terms of \(p\) or \(q\), the coordinates of points at which the curve meets the axes. Given that \(\mathrm { f } ( x ) = 3 \ln ( 2 x + 3 )\),
  2. state the exact value of \(q\),
  3. find the value of \(p\),
  4. find an equation for the tangent to the curve at \(P\).

Question 5:
Part (a)(i):
AnswerMarks Guidance
Answer/WorkingMarks Notes
Shape correctB1
Intercepts labelled \(p\) on \(x\)-axis and \(q\) on \(y\)-axisB1 (2)
Part (a)(ii):
AnswerMarks Guidance
Answer/WorkingMarks Notes
Shape correctB1
\((2p, 0)\) on \(x\)-axisB1
\((0, 3q)\) on \(y\)-axisB1 (3)
Part (b):
AnswerMarks Guidance
Answer/WorkingMarks Notes
\(q = 3\ln 3\)B1 (1)
Part (c):
AnswerMarks Guidance
Answer/WorkingMarks Notes
\(\ln(2p+3) = 0 \Rightarrow 2p+3 = 1\); \(p = -1\)M1 A1 (2)
Part (d):
AnswerMarks Guidance
Answer/WorkingMarks Notes
\(\frac{dy}{dx} = \frac{6}{2x+3}\); evaluated at \(x = p\)M1 A1
Equation: \(y = 6(x+1)\) any formM1 A1ft (4)
## Question 5:

### Part (a)(i):

| Answer/Working | Marks | Notes |
|---|---|---|
| Shape correct | B1 | |
| Intercepts labelled $p$ on $x$-axis and $q$ on $y$-axis | B1 | **(2)** |

### Part (a)(ii):

| Answer/Working | Marks | Notes |
|---|---|---|
| Shape correct | B1 | |
| $(2p, 0)$ on $x$-axis | B1 | |
| $(0, 3q)$ on $y$-axis | B1 | **(3)** |

### Part (b):

| Answer/Working | Marks | Notes |
|---|---|---|
| $q = 3\ln 3$ | B1 | **(1)** |

### Part (c):

| Answer/Working | Marks | Notes |
|---|---|---|
| $\ln(2p+3) = 0 \Rightarrow 2p+3 = 1$; $p = -1$ | M1 A1 | **(2)** |

### Part (d):

| Answer/Working | Marks | Notes |
|---|---|---|
| $\frac{dy}{dx} = \frac{6}{2x+3}$; evaluated at $x = p$ | M1 A1 | |
| Equation: $y = 6(x+1)$ any form | M1 A1ft | **(4)** |

---
5.

\begin{figure}[h]
\begin{center}
\captionsetup{labelformat=empty}
\caption{Figure 1}
  \includegraphics[alt={},max width=\textwidth]{937edb48-ef4c-4974-a571-60b0fded841b-3_394_680_982_680}
\end{center}
\end{figure}

Figure 1 shows part of the curve with equation $y = \mathrm { f } ( x ) , x \in \mathbb { R }$. The curve meets the $x$-axis at $P ( p , 0 )$ and meets the $y$-axis at $Q ( 0 , q )$.
\begin{enumerate}[label=(\alph*)]
\item On separate diagrams, sketch the curve with equation
\begin{enumerate}[label=(\roman*)]
\item $y = | \mathrm { f } ( x ) |$,
\item $y = 3 \mathrm { f } \left( \frac { 1 } { 2 } x \right)$.

In each case show, in terms of $p$ or $q$, the coordinates of points at which the curve meets the axes.

Given that $\mathrm { f } ( x ) = 3 \ln ( 2 x + 3 )$,
\end{enumerate}\item state the exact value of $q$,
\item find the value of $p$,
\item find an equation for the tangent to the curve at $P$.
\end{enumerate}

\hfill \mbox{\textit{Edexcel C3  Q5 [12]}}