| Exam Board | OCR MEI |
|---|---|
| Module | C1 (Core Mathematics 1) |
| Marks | 5 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Indices and Surds |
| Type | Rationalize denominator simple |
| Difficulty | Easy -1.2 Part (i) is straightforward index law recall (negative fractional power). Part (ii) requires rationalizing denominators and combining fractions, which is a standard C1 technique but involves more steps. Overall, this is a routine algebraic manipulation question with no problem-solving insight required, making it easier than average. |
| Spec | 1.02a Indices: laws of indices for rational exponents1.02b Surds: manipulation and rationalising denominators |
| Answer | Marks |
|---|---|
| 4 (i) | 1 1 |
| Answer | Marks | Guidance |
|---|---|---|
| 12 12 | 2 | 1 |
| Answer | Marks |
|---|---|
| 4 (ii) | denominator = 18 |
| Answer | Marks |
|---|---|
| = 25+3 7 as final answer | B1 |
| Answer | Marks |
|---|---|
| A1 | B0 if 36 after addition |
Question 4:
--- 4 (i) ---
4 (i) | 1 1
or ±
12 12 | 2 | 1
M1 for o.e. or for 144 =12 soi
1
1442
--- 4 (ii) ---
4 (ii) | denominator = 18
( )
numerator = 5− 7 +4 5+ 7
= 25+3 7 as final answer | B1
M1
A1 | B0 if 36 after addition
for M1, allow in separate fractions
25+3 7
allow B3 for as final answer
18
www\begin{enumerate}[label=(\roman*)]
\item Find the value of $144^{-\frac{1}{2}}$. [2]
\item Simplify $\frac{1}{5 + \sqrt{7}} + \frac{4}{5 - \sqrt{7}}$. Give your answer in the form $\frac{a + b\sqrt{7}}{c}$. [3]
\end{enumerate}
\hfill \mbox{\textit{OCR MEI C1 Q4 [5]}}