| Exam Board | Edexcel |
|---|---|
| Module | C1 (Core Mathematics 1) |
| Marks | 4 |
| Paper | Download PDF ↗ |
| Topic | Discriminant and conditions for roots |
| Type | Find k for equal roots |
| Difficulty | Moderate -0.8 This is a straightforward application of the discriminant condition for equal roots (b² - 4ac = 0) with simple algebraic manipulation. It's easier than average because it's a direct, single-concept question requiring only recall of the discriminant formula and solving a basic equation, though the presence of k in two positions adds minimal complexity. |
| Spec | 1.02d Quadratic functions: graphs and discriminant conditions1.02f Solve quadratic equations: including in a function of unknown |
Given that the equation $kx^2 + 12x + k = 0$, where $k$ is a positive constant, has equal roots, find the value of $k$. [4]
\hfill \mbox{\textit{Edexcel C1 Q3 [4]}}