OCR MEI Paper 3 2024 June — Question 4 2 marks

Exam BoardOCR MEI
ModulePaper 3 (Paper 3)
Year2024
SessionJune
Marks2
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicIndices and Surds
TypeRationalize denominator simple
DifficultyModerate -0.8 This is a straightforward rationalizing denominators question requiring a standard technique applied three times, then simplification. While it involves multiple terms and careful algebra, it's a routine exercise with no conceptual difficulty or novel insight required—easier than average for A-level.
Spec1.02b Surds: manipulation and rationalising denominators

4 In this question you must show detailed reasoning. Determine the exact value of \(\frac { 1 } { \sqrt { 2 } + 1 } + \frac { 1 } { \sqrt { 3 } + \sqrt { 2 } } + \frac { 1 } { 2 + \sqrt { 3 } }\).

Question 4:
AnswerMarks Guidance
At least one fraction multiplied by \(\frac{\sqrt{2}-1}{\sqrt{2}-1}\) or \(\frac{\sqrt{3}-\sqrt{2}}{\sqrt{3}-\sqrt{2}}\) or \(\frac{2-\sqrt{3}}{2-\sqrt{3}}\)M1 Rationalising denominators method
All correct with denominators seen as \(2-1\), \(3-2\), \(4-3\) or \(1,1,1\); answer 1A1 Must see something correct
Numerator of \((\sqrt{3}+\sqrt{2})(2+\sqrt{3})+(\sqrt{2}+1)(2+\sqrt{3})+(\sqrt{2}+1)(\sqrt{3}+\sqrt{2})\) giving \(3\sqrt{6}+4\sqrt{3}+5\sqrt{2}+7\)M1 Alternative: combining all three fractions
\(\frac{3\sqrt{6}+4\sqrt{3}+5\sqrt{2}+7}{3\sqrt{6}+4\sqrt{3}+5\sqrt{2}+7}\) before cancelling; answer 1A1
## Question 4:
| At least one fraction multiplied by $\frac{\sqrt{2}-1}{\sqrt{2}-1}$ or $\frac{\sqrt{3}-\sqrt{2}}{\sqrt{3}-\sqrt{2}}$ or $\frac{2-\sqrt{3}}{2-\sqrt{3}}$ | M1 | Rationalising denominators method |
| All correct with denominators seen as $2-1$, $3-2$, $4-3$ or $1,1,1$; answer 1 | A1 | Must see something correct |
| Numerator of $(\sqrt{3}+\sqrt{2})(2+\sqrt{3})+(\sqrt{2}+1)(2+\sqrt{3})+(\sqrt{2}+1)(\sqrt{3}+\sqrt{2})$ giving $3\sqrt{6}+4\sqrt{3}+5\sqrt{2}+7$ | M1 | Alternative: combining all three fractions |
| $\frac{3\sqrt{6}+4\sqrt{3}+5\sqrt{2}+7}{3\sqrt{6}+4\sqrt{3}+5\sqrt{2}+7}$ before cancelling; answer 1 | A1 | |
4 In this question you must show detailed reasoning.
Determine the exact value of $\frac { 1 } { \sqrt { 2 } + 1 } + \frac { 1 } { \sqrt { 3 } + \sqrt { 2 } } + \frac { 1 } { 2 + \sqrt { 3 } }$.

\hfill \mbox{\textit{OCR MEI Paper 3 2024 Q4 [2]}}