OCR MEI C1 — Question 9 5 marks

Exam BoardOCR MEI
ModuleC1 (Core Mathematics 1)
Marks5
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicIndices and Surds
TypeSolve power equations
DifficultyEasy -1.2 This is a straightforward C1 question testing basic index laws. Part (i) requires converting to a common base and simplifying - a routine manipulation. Part (ii) is a simple one-step equation solved by raising both sides to the power of -3. Both parts are standard textbook exercises requiring only recall and direct application of index rules with no problem-solving insight needed.
Spec1.02a Indices: laws of indices for rational exponents

9
  1. Simplify \(\frac { 2 ^ { 6 } } { 8 ^ { 2 \frac { 1 } { 2 } } \times 2 ^ { - \frac { 1 } { 2 } } }\)
  2. Solve the equation \(x ^ { - \frac { 1 } { 3 } } = 8\).

Question 9(i):
AnswerMarks Guidance
\(\frac{2^6}{8^{\frac{1}{2}} \times 2^{-\frac{1}{2}}}=\frac{2^6}{2^{7.5} \times 2^{-0.5}}=2^{6-7.5+0.5}=2^{-1}=\frac{1}{2}\)M1 Powers of 2
B1Correct signs
B1
Total: 3
Question 9(ii):
AnswerMarks
\(x^{-\frac{1}{3}}=8 \Rightarrow x^{\frac{1}{3}}=\frac{1}{8} \Rightarrow x=\left(\frac{1}{8}\right)^3=\frac{1}{512}\)M1
A1
Total: 2
## Question 9(i):
$\frac{2^6}{8^{\frac{1}{2}} \times 2^{-\frac{1}{2}}}=\frac{2^6}{2^{7.5} \times 2^{-0.5}}=2^{6-7.5+0.5}=2^{-1}=\frac{1}{2}$ | M1 | Powers of 2
| B1 | Correct signs
| B1 |
**Total: 3**

## Question 9(ii):
$x^{-\frac{1}{3}}=8 \Rightarrow x^{\frac{1}{3}}=\frac{1}{8} \Rightarrow x=\left(\frac{1}{8}\right)^3=\frac{1}{512}$ | M1 |
| A1 |
**Total: 2**

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9 (i) Simplify $\frac { 2 ^ { 6 } } { 8 ^ { 2 \frac { 1 } { 2 } } \times 2 ^ { - \frac { 1 } { 2 } } }$\\
(ii) Solve the equation $x ^ { - \frac { 1 } { 3 } } = 8$.

\hfill \mbox{\textit{OCR MEI C1  Q9 [5]}}