OCR C1 2009 January — Question 3 5 marks

Exam BoardOCR
ModuleC1 (Core Mathematics 1)
Year2009
SessionJanuary
Marks5
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicSolving quadratics and applications
TypeQuadratic in negative or reciprocal fractional powers
DifficultyStandard +0.3 This is a straightforward substitution question where students let u = x^(1/3) to transform it into 3u² + u - 2 = 0, then solve the quadratic and cube the result. While it requires recognizing the substitution pattern and handling fractional indices, it's a standard C1 technique with no conceptual surprises, making it slightly easier than average.
Spec1.02a Indices: laws of indices for rational exponents1.02f Solve quadratic equations: including in a function of unknown

3 Solve the equation \(3 x ^ { \frac { 2 } { 3 } } + x ^ { \frac { 1 } { 3 } } - 2 = 0\).

3 Solve the equation $3 x ^ { \frac { 2 } { 3 } } + x ^ { \frac { 1 } { 3 } } - 2 = 0$.

\hfill \mbox{\textit{OCR C1 2009 Q3 [5]}}