SPS SPS SM Pure 2021 June — Question 10 10 marks

Exam BoardSPS
ModuleSPS SM Pure (SPS SM Pure)
Year2021
SessionJune
Marks10
TopicFactor & Remainder Theorem
TypeIntegration or area using factorised polynomial
DifficultyModerate -0.3 This is a straightforward multi-part question combining factor theorem, polynomial factorization, and definite integration. Part (a) is routine substitution, part (b) requires polynomial division and factoring a quadratic (both standard techniques), and part (c) involves integrating a cubic between given roots. While it requires multiple steps across different topics, each individual step is a standard A-level procedure with no novel problem-solving or insight required, making it slightly easier than average.
Spec1.02j Manipulate polynomials: expanding, factorising, division, factor theorem1.08e Area between curve and x-axis: using definite integrals

$$g(x) = 2x^3 + x^2 - 41x - 70$$
  1. Use the factor theorem to show that \(g(x)\) is divisible by \((x - 5)\). [2]
  2. Hence, showing all your working, write \(g(x)\) as a product of three linear factors. [4]
The finite region \(R\) is bounded by the curve with equation \(y = g(x)\) and the \(x\)-axis, and lies below the \(x\)-axis.
  1. Find, using algebraic integration, the exact value of the area of \(R\). [4]

$$g(x) = 2x^3 + x^2 - 41x - 70$$

\begin{enumerate}[label=(\alph*)]
\item Use the factor theorem to show that $g(x)$ is divisible by $(x - 5)$. [2]
\item Hence, showing all your working, write $g(x)$ as a product of three linear factors. [4]
\end{enumerate}

The finite region $R$ is bounded by the curve with equation $y = g(x)$ and the $x$-axis, and lies below the $x$-axis.

\begin{enumerate}[label=(\alph*)]
\setcounter{enumi}{2}
\item Find, using algebraic integration, the exact value of the area of $R$. [4]
\end{enumerate}

\hfill \mbox{\textit{SPS SPS SM Pure 2021 Q10 [10]}}