| Exam Board | OCR |
|---|---|
| Module | C1 (Core Mathematics 1) |
| Year | 2008 |
| Session | June |
| Marks | 5 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Solving quadratics and applications |
| Type | Quadratic in x^(1/2) - substitution u = √x |
| Difficulty | Standard +0.3 This is a standard substitution question where students let u = x^(1/2) to convert to a quadratic in u, then solve and back-substitute. It's a routine C1 technique that's slightly easier than average since the substitution is obvious and the resulting quadratic 2u² - 7u + 3 = 0 factors cleanly, though students must remember to reject negative solutions when squaring. |
| Spec | 1.02a Indices: laws of indices for rational exponents1.02f Solve quadratic equations: including in a function of unknown |
4 Solve the equation $2 x - 7 x ^ { \frac { 1 } { 2 } } + 3 = 0$.
\hfill \mbox{\textit{OCR C1 2008 Q4 [5]}}