CAIE P1 2023 June — Question 7 5 marks

Exam BoardCAIE
ModuleP1 (Pure Mathematics 1)
Year2023
SessionJune
Marks5
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicCurve Sketching
TypeTrigonometric curve intersections
DifficultyStandard +0.3 This is a straightforward curve sketching question requiring basic knowledge of sine transformations (amplitude, vertical shift, period adjustment) and graphical intersection counting. Part (a) is simple arithmetic with sine range, part (b) is standard sketching, and part (c) requires only visual inspection of intersections—no algebraic solving needed. Slightly easier than average due to routine nature.
Spec1.02m Graphs of functions: difference between plotting and sketching1.02q Use intersection points: of graphs to solve equations1.05f Trigonometric function graphs: symmetries and periodicities

7 A curve has equation \(y = 2 + 3 \sin \frac { 1 } { 2 } x\) for \(0 \leqslant x \leqslant 4 \pi\).
  1. State greatest and least values of \(y\).
  2. Sketch the curve. \includegraphics[max width=\textwidth, alt={}, center]{77f27b11-b931-481f-b4ef-5e549eff8086-09_1127_1219_904_495}
  3. State the number of solutions of the equation $$2 + 3 \sin \frac { 1 } { 2 } x = 5 - 2 x$$ for \(0 \leqslant x \leqslant 4 \pi\).

Question 7(a):
AnswerMarks Guidance
AnswerMarks Guidance
Greatest \(= 5\)B1 No inequality required
Least \(= -1\)B1 No inequality required. Condone \((-1, 5)\) or equivalent
Question 7(b):
AnswerMarks Guidance
AnswerMarks Guidance
One complete cycle starting and finishing at \(y=2\), maximum and minimum in correct quadrants, shape and curvature approximately correctB1 One complete cycle starting and finishing at \(y=2\). Maximum and minimum in correct quadrants. Shape and curvature approximately correct
Maximum and minimum indicated on \(y\)-axis with numbers or lines, or labelled on graphB1 FT FT *their* greatest and least values. Award B1 for 5 and \(-1\) even if *their* values were incorrect in (a)
Question 7(c):
AnswerMarks Guidance
AnswerMarks Guidance
\(1\)B1 WWW
## Question 7(a):

| Answer | Marks | Guidance |
|--------|-------|----------|
| Greatest $= 5$ | B1 | No inequality required |
| Least $= -1$ | B1 | No inequality required. Condone $(-1, 5)$ or equivalent |

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## Question 7(b):

| Answer | Marks | Guidance |
|--------|-------|----------|
| One complete cycle starting and finishing at $y=2$, maximum and minimum in correct quadrants, shape and curvature approximately correct | B1 | One complete cycle starting and finishing at $y=2$. Maximum and minimum in correct quadrants. Shape and curvature approximately correct |
| Maximum and minimum indicated on $y$-axis with numbers or lines, or labelled on graph | B1 FT | FT *their* greatest and least values. Award B1 for 5 and $-1$ even if *their* values were incorrect in (a) |

---

## Question 7(c):

| Answer | Marks | Guidance |
|--------|-------|----------|
| $1$ | B1 | WWW |

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7 A curve has equation $y = 2 + 3 \sin \frac { 1 } { 2 } x$ for $0 \leqslant x \leqslant 4 \pi$.
\begin{enumerate}[label=(\alph*)]
\item State greatest and least values of $y$.
\item Sketch the curve.\\
\includegraphics[max width=\textwidth, alt={}, center]{77f27b11-b931-481f-b4ef-5e549eff8086-09_1127_1219_904_495}
\item State the number of solutions of the equation

$$2 + 3 \sin \frac { 1 } { 2 } x = 5 - 2 x$$

for $0 \leqslant x \leqslant 4 \pi$.
\end{enumerate}

\hfill \mbox{\textit{CAIE P1 2023 Q7 [5]}}