Edexcel C2 — Question 29 7 marks

Exam BoardEdexcel
ModuleC2 (Core Mathematics 2)
Marks7
PaperDownload PDF ↗
TopicFactor & Remainder Theorem
TypeTwo unknowns, direct system
DifficultyModerate -0.3 This is a standard C2 Factor/Remainder Theorem question requiring straightforward application of f(3)=14 and f(-1)=-18 to form simultaneous equations, then solving for a and b. Part (b) is routine verification by substitution. While it involves multiple steps (7 marks total), the techniques are purely procedural with no problem-solving insight required, making it slightly easier than average.
Spec1.02j Manipulate polynomials: expanding, factorising, division, factor theorem

$$f(x) = x^3 + ax^2 + bx - 10, \text{ where } a \text{ and } b \text{ are constants.}$$ When \(f(x)\) is divided by \((x - 3)\), the remainder is 14. When \(f(x)\) is divided by \((x + 1)\), the remainder is \(-18\).
  1. Find the value of \(a\) and the value of \(b\). [5]
  2. Show that \((x - 2)\) is a factor of \(f(x)\). [2]

$$f(x) = x^3 + ax^2 + bx - 10, \text{ where } a \text{ and } b \text{ are constants.}$$

When $f(x)$ is divided by $(x - 3)$, the remainder is 14.

When $f(x)$ is divided by $(x + 1)$, the remainder is $-18$.

\begin{enumerate}[label=(\alph*)]
\item Find the value of $a$ and the value of $b$. [5]

\item Show that $(x - 2)$ is a factor of $f(x)$. [2]
\end{enumerate}

\hfill \mbox{\textit{Edexcel C2  Q29 [7]}}