WJEC Unit 1 2023 June — Question 4 10 marks

Exam BoardWJEC
ModuleUnit 1 (Unit 1)
Year2023
SessionJune
Marks10
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicFactor & Remainder Theorem
TypeRemainder condition then further work
DifficultyModerate -0.8 This is a straightforward polynomial question testing the Remainder Theorem and Factor Theorem with standard techniques. Part (a) requires direct substitution (x=3), part (b)(i) uses f(-2)=0 to find a constant, and part (b)(ii) involves factoring a cubic after finding one root—all routine AS-level procedures with no problem-solving insight required. The 10 marks reflect multiple steps rather than conceptual difficulty.
Spec1.02j Manipulate polynomials: expanding, factorising, division, factor theorem

  1. Find the remainder when the polynomial \(3x^3 + 2x^2 + x - 1\) is divided by \((x - 3)\). [3]
  2. The polynomial \(f(x) = 2x^3 - 3x^2 + ax + 6\) is divisible by \((x + 2)\), where \(a\) is a real constant.
    1. Find the value of \(a\). [3]
    2. Showing all your working, solve the equation \(f(x) = 0\). [4]

\begin{enumerate}[label=(\alph*)]
\item Find the remainder when the polynomial $3x^3 + 2x^2 + x - 1$ is divided by $(x - 3)$. [3]

\item The polynomial $f(x) = 2x^3 - 3x^2 + ax + 6$ is divisible by $(x + 2)$, where $a$ is a real constant.
\begin{enumerate}[label=(\roman*)]
\item Find the value of $a$. [3]

\item Showing all your working, solve the equation $f(x) = 0$. [4]
\end{enumerate}
\end{enumerate}

\hfill \mbox{\textit{WJEC Unit 1 2023 Q4 [10]}}