OCR C1 — Question 6 7 marks

Exam BoardOCR
ModuleC1 (Core Mathematics 1)
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicIndices and Surds
TypeSolve power equations
DifficultyModerate -0.3 This is a straightforward C1 question on fractional indices. Part (i) requires substitution and simplification with rationalizing, which is routine. Part (ii) involves factoring out x^(-1/2) and solving a simple quadratic-type equation. Both parts use standard techniques with no problem-solving insight required, making it slightly easier than average but not trivial due to the algebraic manipulation needed.
Spec1.02a Indices: laws of indices for rational exponents1.02b Surds: manipulation and rationalising denominators

6. $$f ( x ) = x ^ { \frac { 3 } { 2 } } - 8 x ^ { - \frac { 1 } { 2 } }$$
  1. Evaluate \(\mathrm { f } ( 3 )\), giving your answer in its simplest form with a rational denominator.
  2. Solve the equation \(\mathrm { f } ( x ) = 0\), giving your answers in the form \(k \sqrt { 2 }\).

6.

$$f ( x ) = x ^ { \frac { 3 } { 2 } } - 8 x ^ { - \frac { 1 } { 2 } }$$

(i) Evaluate $\mathrm { f } ( 3 )$, giving your answer in its simplest form with a rational denominator.\\
(ii) Solve the equation $\mathrm { f } ( x ) = 0$, giving your answers in the form $k \sqrt { 2 }$.\\

\hfill \mbox{\textit{OCR C1  Q6 [7]}}