OCR MEI C1 2009 January — Question 10 5 marks

Exam BoardOCR MEI
ModuleC1 (Core Mathematics 1)
Year2009
SessionJanuary
Marks5
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicStraight Lines & Coordinate Geometry
TypeDistance between two points
DifficultyEasy -1.2 This is a straightforward C1 question testing basic algebraic manipulation (simplifying surds and rationalizing denominators) and likely the distance formula. Part (i) requires factorizing radicals and combining like terms; part (ii) is standard rationalization. These are routine textbook exercises requiring only recall and direct application of techniques, making them easier than average A-level questions.
Spec1.02b Surds: manipulation and rationalising denominators

10
  1. Express \(\sqrt { 75 } + \sqrt { 48 }\) in the form \(a \sqrt { 3 }\).
  2. Express \(\frac { 14 } { 3 - \sqrt { 2 } }\) in the form \(b + c \sqrt { d }\). \begin{figure}[h]
    \includegraphics[alt={},max width=\textwidth]{c7fbeb8f-d874-4756-aa53-5471b215902f-3_773_961_354_591} \captionsetup{labelformat=empty} \caption{Fig. 11}
    \end{figure} Fig. 11 shows the points A and B , which have coordinates \(( - 1,0 )\) and \(( 11,4 )\) respectively.

Question 10:
Part (i):
AnswerMarks Guidance
Answer/WorkingMark Guidance
\(9\sqrt{3}\)2 M1 for \(5\sqrt{3}\) or \(4\sqrt{3}\) seen
Part (ii):
AnswerMarks Guidance
Answer/WorkingMark Guidance
\(6 + 2\sqrt{2}\) www3 M1 for attempt to multiply num. and denom. by \(3 + \sqrt{2}\); M1 for denom. 7 or \(9 - 2\) soi from denom. mult by \(3 + \sqrt{2}\)
Total: 5 marks
# Question 10:

## Part (i):
| Answer/Working | Mark | Guidance |
|---|---|---|
| $9\sqrt{3}$ | 2 | M1 for $5\sqrt{3}$ or $4\sqrt{3}$ seen |

## Part (ii):
| Answer/Working | Mark | Guidance |
|---|---|---|
| $6 + 2\sqrt{2}$ www | 3 | M1 for attempt to multiply num. and denom. by $3 + \sqrt{2}$; M1 for denom. 7 or $9 - 2$ soi from denom. mult by $3 + \sqrt{2}$ |
| **Total: 5 marks** | | |

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10 (i) Express $\sqrt { 75 } + \sqrt { 48 }$ in the form $a \sqrt { 3 }$.\\
(ii) Express $\frac { 14 } { 3 - \sqrt { 2 } }$ in the form $b + c \sqrt { d }$.

\begin{figure}[h]
\begin{center}
  \includegraphics[alt={},max width=\textwidth]{c7fbeb8f-d874-4756-aa53-5471b215902f-3_773_961_354_591}
\captionsetup{labelformat=empty}
\caption{Fig. 11}
\end{center}
\end{figure}

Fig. 11 shows the points A and B , which have coordinates $( - 1,0 )$ and $( 11,4 )$ respectively.\\

\hfill \mbox{\textit{OCR MEI C1 2009 Q10 [5]}}