OCR C1 2006 January — Question 1 4 marks

Exam BoardOCR
ModuleC1 (Core Mathematics 1)
Year2006
SessionJanuary
Marks4
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicIndices and Surds
TypeSolve power equations
DifficultyEasy -1.8 This is a straightforward recall question testing basic index laws with no problem-solving required. Each part involves a single-step manipulation: (i) cube both sides, (ii) recognize that any number to power 0 equals 1, (iii) simplify the left side then take fourth roots. These are routine textbook exercises significantly easier than average A-level questions.
Spec1.02a Indices: laws of indices for rational exponents

1 Solve the equations
  1. \(x ^ { \frac { 1 } { 3 } } = 2\),
  2. \(10 ^ { \prime } = 1\),
  3. \(\left( y ^ { - 2 } \right) ^ { 2 } = \frac { 1 } { 81 }\).

AnswerMarks Guidance
(i) \(\frac{1}{x^3} = 2\), \(x = 8\)B1, I, 8 Allow embedded values throughout question 1
(ii) \(10^t = 1\), \(t = 0\)B1, 1, 0
(iii) \((y^{-3})^2 = \frac{1}{81}\), \(y^{-4} = \frac{1}{81}\), \(y = \pm 3\)B1, B1, 2 \(y = 3\); \(y = -3\)
**(i)** $\frac{1}{x^3} = 2$, $x = 8$ | B1, I, 8 | Allow embedded values throughout question 1

**(ii)** $10^t = 1$, $t = 0$ | B1, 1, 0 |

**(iii)** $(y^{-3})^2 = \frac{1}{81}$, $y^{-4} = \frac{1}{81}$, $y = \pm 3$ | B1, B1, 2 | $y = 3$; $y = -3$
1 Solve the equations\\
(i) $x ^ { \frac { 1 } { 3 } } = 2$,\\
(ii) $10 ^ { \prime } = 1$,\\
(iii) $\left( y ^ { - 2 } \right) ^ { 2 } = \frac { 1 } { 81 }$.

\hfill \mbox{\textit{OCR C1 2006 Q1 [4]}}