OCR C1 — Question 7 10 marks

Exam BoardOCR
ModuleC1 (Core Mathematics 1)
Marks10
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicFunction Transformations
TypeIdentify transformation from equations
DifficultyStandard +0.3 This is a straightforward C1 question testing basic transformation knowledge, sketching a simple rational function, and solving a quadratic equation. Part (i) is pure recall, part (ii) is routine sketching, and part (iii) involves standard algebraic manipulation leading to a quadratic with surds—all well-practiced techniques at this level with no novel problem-solving required.
Spec1.02o Sketch reciprocal curves: y=a/x and y=a/x^21.02q Use intersection points: of graphs to solve equations1.02w Graph transformations: simple transformations of f(x)

  1. Describe fully the single transformation that maps the graph of \(y = f(x)\) onto the graph of \(y = f(x - 1)\). [2]
  2. Showing the coordinates of any points of intersection with the coordinate axes and the equations of any asymptotes, sketch the graph of \(y = \frac{1}{x-1}\). [3]
  3. Find the \(x\)-coordinates of any points where the graph of \(y = \frac{1}{x-1}\) intersects the graph of \(y = 2 + \frac{1}{x}\). Give your answers in the form \(a + b\sqrt{3}\), where \(a\) and \(b\) are rational. [5]

(i)
AnswerMarks
Translation by 1 unit in the positive \(x\)-directionB2
(ii)
AnswerMarks
[Graph showing curve with vertical asymptote at \(x=1\), horizontal asymptote at \(y=0\), and point at \((0,-1)\)]B3
(iii)
AnswerMarks Guidance
\(\frac{1}{x-1} = 2 + \frac{1}{x}\)M1
\(x = 2x(x-1) + (x-1)\)A1
\(2x^2 - 2x - 1 = 0\)M1
\(x = \frac{2 \pm \sqrt{4+8}}{4}\)M1
\(x = \frac{2 \pm 2\sqrt{3}}{4}\)M1
\(x = \frac{1}{2} \pm \frac{1}{2}\sqrt{3}\)A1 (10)
## (i)
Translation by 1 unit in the positive $x$-direction | B2 |

## (ii)
[Graph showing curve with vertical asymptote at $x=1$, horizontal asymptote at $y=0$, and point at $(0,-1)$] | B3 |

## (iii)
$\frac{1}{x-1} = 2 + \frac{1}{x}$ | M1 |
$x = 2x(x-1) + (x-1)$ | A1 |
$2x^2 - 2x - 1 = 0$ | M1 |
$x = \frac{2 \pm \sqrt{4+8}}{4}$ | M1 |
$x = \frac{2 \pm 2\sqrt{3}}{4}$ | M1 |
$x = \frac{1}{2} \pm \frac{1}{2}\sqrt{3}$ | A1 | (10) |

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\begin{enumerate}[label=(\roman*)]
\item Describe fully the single transformation that maps the graph of $y = f(x)$ onto the graph of $y = f(x - 1)$. [2]

\item Showing the coordinates of any points of intersection with the coordinate axes and the equations of any asymptotes, sketch the graph of $y = \frac{1}{x-1}$. [3]

\item Find the $x$-coordinates of any points where the graph of $y = \frac{1}{x-1}$ intersects the graph of $y = 2 + \frac{1}{x}$. Give your answers in the form $a + b\sqrt{3}$, where $a$ and $b$ are rational. [5]
\end{enumerate}

\hfill \mbox{\textit{OCR C1  Q7 [10]}}