Edexcel P1 2024 June — Question 11 6 marks

Exam BoardEdexcel
ModuleP1 (Pure Mathematics 1)
Year2024
SessionJune
Marks6
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicTrig Graphs & Exact Values
TypeFind coordinates of turning points
DifficultyModerate -0.8 This is a straightforward question testing basic understanding of sine graph transformations. Part (a) requires knowing sin x has maximum value 1 at x=π/2. Part (b) involves a simple vertical translation. Part (c) requires understanding horizontal translations and that minimum occurs when sin=-1. All parts are routine applications of standard transformations with no problem-solving or novel insight required.
Spec1.05f Trigonometric function graphs: symmetries and periodicities

11.
Figure 4 shows a sketch of part of the curve \(C _ { 1 }\) with equation $$y = 12 \sin x$$ where \(x\) is measured in radians.
The point \(P\) shown in Figure 4 is a maximum point on \(C _ { 1 }\)
  1. Find the coordinates of \(P\). The curve \(C _ { 2 }\) has equation $$y = 12 \sin x + k$$ where \(k\) is a constant.
    Given that the maximum value of \(y\) on \(C _ { 2 }\) is 3
  2. find the coordinates of the minimum point on \(C _ { 2 }\) which has the smallest positive \(x\) coordinate. The curve \(C _ { 3 }\) has equation $$y = 12 \sin ( x + B )$$ where \(B\) is a positive constant.
    Given that \(\left( \frac { \pi } { 4 } , A \right)\), where \(A\) is a constant, is the minimum point on \(C _ { 3 }\) which has the smallest positive \(x\) coordinate,
  3. find
    1. the value of \(A\),
    2. the smallest possible value of \(B\).

Question 11:
Part (a):
AnswerMarks Guidance
Answer/WorkingMark Guidance
\(x = \frac{5\pi}{2}\) or \(y = 12\)B1 One coordinate correct; may be in coordinate pair or vector
\(x = \frac{5\pi}{2}\) and \(y = 12\)B1 Both coordinates correct
(2 marks)
Part (b):
AnswerMarks Guidance
Answer/WorkingMark Guidance
\(x = \frac{3\pi}{2}\) or \(y = -21\)B1 One coordinate correct
\(x = \frac{3\pi}{2}\) and \(y = -21\)B1 Both coordinates correct
(2 marks)
Part (c)(i):
AnswerMarks Guidance
Answer/WorkingMark Guidance
\(A = -12\)B1 "\(A=\)" not required but must be clear it is the answer to (i)
Part (c)(ii):
AnswerMarks Guidance
Answer/WorkingMark Guidance
\(B = \frac{5\pi}{4}\)B1 "\(B=\)" not required but must be clear it is the answer to (ii); if written as coordinate pair \(\left(\frac{5\pi}{4}, -12\right)\) score B0B0
(2 marks) — Total 6
## Question 11:

### Part (a):

| Answer/Working | Mark | Guidance |
|---|---|---|
| $x = \frac{5\pi}{2}$ or $y = 12$ | B1 | One coordinate correct; may be in coordinate pair or vector |
| $x = \frac{5\pi}{2}$ and $y = 12$ | B1 | Both coordinates correct |

**(2 marks)**

### Part (b):

| Answer/Working | Mark | Guidance |
|---|---|---|
| $x = \frac{3\pi}{2}$ or $y = -21$ | B1 | One coordinate correct |
| $x = \frac{3\pi}{2}$ and $y = -21$ | B1 | Both coordinates correct |

**(2 marks)**

### Part (c)(i):

| Answer/Working | Mark | Guidance |
|---|---|---|
| $A = -12$ | B1 | "$A=$" not required but must be clear it is the answer to (i) |

### Part (c)(ii):

| Answer/Working | Mark | Guidance |
|---|---|---|
| $B = \frac{5\pi}{4}$ | B1 | "$B=$" not required but must be clear it is the answer to (ii); if written as coordinate pair $\left(\frac{5\pi}{4}, -12\right)$ score B0B0 |

**(2 marks) — Total 6**
11.

\begin{tikzpicture}[scale=0.55]
  % Axes
  \draw[->] (-3.5,0) -- (10.5,0) node[right] {$x$};
  \draw[->] (0,-14) -- (0,15) node[above] {$y$};
  \node[below left] at (0,0) {$O$};

  % Curve y = 12 sin x
  \draw[thick, domain=-3.14:9.9, samples=200] plot (\x, {12*sin(\x r)});

  % Point P at (pi/2, 12)
  \fill (1.5708,12) circle (3pt);
  \node[above right] at (1.5708,12) {$P$};
\end{tikzpicture}

Figure 4 shows a sketch of part of the curve $C _ { 1 }$ with equation

$$y = 12 \sin x$$

where $x$ is measured in radians.\\
The point $P$ shown in Figure 4 is a maximum point on $C _ { 1 }$
\begin{enumerate}[label=(\alph*)]
\item Find the coordinates of $P$.

The curve $C _ { 2 }$ has equation

$$y = 12 \sin x + k$$

where $k$ is a constant.\\
Given that the maximum value of $y$ on $C _ { 2 }$ is 3
\item find the coordinates of the minimum point on $C _ { 2 }$ which has the smallest positive $x$ coordinate.

The curve $C _ { 3 }$ has equation

$$y = 12 \sin ( x + B )$$

where $B$ is a positive constant.\\
Given that $\left( \frac { \pi } { 4 } , A \right)$, where $A$ is a constant, is the minimum point on $C _ { 3 }$ which has the smallest positive $x$ coordinate,
\item find
\begin{enumerate}[label=(\roman*)]
\item the value of $A$,
\item the smallest possible value of $B$.
\end{enumerate}\end{enumerate}

\hfill \mbox{\textit{Edexcel P1 2024 Q11 [6]}}