| Exam Board | Edexcel |
|---|---|
| Module | C1 (Core Mathematics 1) |
| Marks | 7 |
| Paper | Download PDF ↗ |
| Topic | Completing the square and sketching |
| Type | Quadratic with equal roots |
| Difficulty | Moderate -0.8 This is a straightforward C1 question testing basic quadratic skills: factorising (part a) and using the discriminant condition b²-4ac=0 for equal roots (part b). Both parts require only routine algebraic manipulation with no problem-solving insight needed, making it easier than average but not trivial since it involves multiple steps and the discriminant concept. |
| Spec | 1.02d Quadratic functions: graphs and discriminant conditions1.02f Solve quadratic equations: including in a function of unknown |
\begin{enumerate}[label=(\alph*)]
\item Solve the equation $4x^2 + 12x = 0$. [3]
\end{enumerate}
$f(x) = 4x^2 + 12x + c$,
where $c$ is a constant.
\begin{enumerate}[label=(\alph*)]
\setcounter{enumi}{1}
\item Given that $f(x) = 0$ has equal roots, find the value of $c$ and hence solve $f(x) = 0$. [4]
\end{enumerate}
\hfill \mbox{\textit{Edexcel C1 Q30 [7]}}