CAIE P1 2023 November — Question 6 8 marks

Exam BoardCAIE
ModuleP1 (Pure Mathematics 1)
Year2023
SessionNovember
Marks8
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicFunction Transformations
TypeCombined stretch and translation
DifficultyModerate -0.3 This is a straightforward multi-part question on completing the square and applying transformations. Part (a) is routine (completing the square or differentiation), parts (b) and (c) require systematic application of transformation rules but involve no novel insight—slightly easier than a typical A-level question due to the mechanical nature of the transformations.
Spec1.02e Complete the square: quadratic polynomials and turning points1.02w Graph transformations: simple transformations of f(x)1.02x Combinations of transformations: multiple transformations

The equation of a curve is \(y = x^2 - 8x + 5\).
  1. Find the coordinates of the minimum point of the curve. [2]
The curve is stretched by a factor of 2 parallel to the \(y\)-axis and then translated by \(\begin{pmatrix} 4 \\ 1 \end{pmatrix}\).
  1. Find the coordinates of the minimum point of the transformed curve. [2]
  2. Find the equation of the transformed curve. Give the answer in the form \(y = ax^2 + bx + c\), where \(a\), \(b\) and \(c\) are integers to be found. [4]

Question 6:

AnswerMarks Guidance
6(a)d ( x2 −8x+5 ) =0  2x−8 = 0 
dxM1 dy
Correct differentiation of x2 and equating their to 0.
dx
Alternative method 1 for first mark of Question 6(a)
AnswerMarks Guidance
y=(x−4)2 −11M1 y=(x−4)2k
Attempt to complete the square as far as .
Alternative method 2 for first mark of Question 6(a)
−b 8
x= =
AnswerMarks Guidance
2a 2M1
x=4,y=-11A1 8 64−20
Answers from x= leading to x=4 11
2
scores M0A0
2

AnswerMarks Guidance
6(b)x=(their x value from a )+4 [=8] B1 FT
dy
differentiating and putting =0.
dx
AnswerMarks Guidance
y= (their y value from a)2  +1 [−21]B1 FT Can be from putting x = 8 in the equation of the transformed
curve.
AnswerMarks Guidance
2If B0B0 scored, SC B1 for sight of (4,−22) .
QuestionAnswer Marks

AnswerMarks Guidance
6(c)2 ( x2 −8x+5 ) or 2{(x−4)2 −11} B1
( )
2 (x−4)2 −8(x−4)+5 +1 OE.
( )  
AnswerMarks Guidance
(x−4)2 −8(x−4)+5 +1 or (x−4−4)2 −their11 +1M1 For the x translation, each x becomes (x−4).
M1For the y translation of +1.
y=2x2 −32x+107 or a=2, b=−32, c=107A1 Evidence to support their answer may be in (b) but answer
must be seen in (c).
4
AnswerMarks Guidance
QuestionAnswer Marks
Question 6:
--- 6(a) ---
6(a) | d ( x2 −8x+5 ) =0  2x−8 = 0 
dx | M1 | dy
Correct differentiation of x2 and equating their to 0.
dx
Alternative method 1 for first mark of Question 6(a)
y=(x−4)2 −11 | M1 | y=(x−4)2k
Attempt to complete the square as far as .
Alternative method 2 for first mark of Question 6(a)
−b 8
x= =
2a 2 | M1
x=4,y=-11 | A1 | 8 64−20
Answers from x= leading to x=4 11
2
scores M0A0
2
--- 6(b) ---
6(b) | x=(their x value from a )+4 [=8] | B1 FT | Can be from finding the equation of the transformed curve,
dy
differentiating and putting =0.
dx
y= (their y value from a)2  +1 [−21] | B1 FT | Can be from putting x = 8 in the equation of the transformed
curve.
2 | If B0B0 scored, SC B1 for sight of (4,−22) .
Question | Answer | Marks | Guidance
--- 6(c) ---
6(c) | 2 ( x2 −8x+5 ) or 2{(x−4)2 −11} | B1 | Can be implied if both transformations done together:
( )
2 (x−4)2 −8(x−4)+5 +1 OE.
( )  
(x−4)2 −8(x−4)+5 +1 or (x−4−4)2 −their11 +1 | M1 | For the x translation, each x becomes (x−4).
M1 | For the y translation of +1.
y=2x2 −32x+107 or a=2, b=−32, c=107 | A1 | Evidence to support their answer may be in (b) but answer
must be seen in (c).
4
Question | Answer | Marks | Guidance
The equation of a curve is $y = x^2 - 8x + 5$.

\begin{enumerate}[label=(\alph*)]
\item Find the coordinates of the minimum point of the curve. [2]
\end{enumerate}

The curve is stretched by a factor of 2 parallel to the $y$-axis and then translated by $\begin{pmatrix} 4 \\ 1 \end{pmatrix}$.

\begin{enumerate}[label=(\alph*)]
\setcounter{enumi}{1}
\item Find the coordinates of the minimum point of the transformed curve. [2]

\item Find the equation of the transformed curve. Give the answer in the form $y = ax^2 + bx + c$, where $a$, $b$ and $c$ are integers to be found. [4]
\end{enumerate}

\hfill \mbox{\textit{CAIE P1 2023 Q6 [8]}}