| Exam Board | Edexcel |
|---|---|
| Module | C1 (Core Mathematics 1) |
| Marks | 6 |
| Paper | Download PDF ↗ |
| Topic | Discriminant and conditions for roots |
| Type | Find k for equal roots |
| Difficulty | Moderate -0.8 This is a straightforward discriminant question requiring recall of the equal roots condition (b² - 4ac = 0) and solving a resulting quadratic equation in p. The steps are routine: set discriminant to zero, expand, solve for p (given it's positive), then substitute back. While it requires multiple steps (4+2 marks), it's a standard textbook exercise with no problem-solving insight needed, making it easier than average for A-level. |
| Spec | 1.02d Quadratic functions: graphs and discriminant conditions1.02f Solve quadratic equations: including in a function of unknown |
The equation $x^2 + 2px + (3p + 4) = 0$, where $p$ is a positive constant, has equal roots.
\begin{enumerate}[label=(\alph*)]
\item Find the value of $p$. [4]
\item For this value of $p$, solve the equation $x^2 + 2px + (3p + 4) = 0$. [2]
\end{enumerate}
\hfill \mbox{\textit{Edexcel C1 Q8 [6]}}