| Exam Board | OCR |
|---|---|
| Module | C1 (Core Mathematics 1) |
| Year | 2010 |
| Session | January |
| Marks | 4 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Discriminant and conditions for roots |
| Type | Find k for equal roots |
| Difficulty | Moderate -0.3 This is a straightforward application of the discriminant condition b² - 4ac = 0 for equal roots. Students need to substitute values, solve a simple quadratic equation, and recognize both solutions are valid. It's slightly easier than average as it's a direct, single-concept question with no problem-solving insight required, though it does require careful algebraic manipulation. |
| Spec | 1.02d Quadratic functions: graphs and discriminant conditions |
10 The quadratic equation $k x ^ { 2 } - 30 x + 25 k = 0$ has equal roots. Find the possible values of $k$.
\hfill \mbox{\textit{OCR C1 2010 Q10 [4]}}