OCR C2 — Question 4 8 marks

Exam BoardOCR
ModuleC2 (Core Mathematics 2)
Marks8
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicPolynomial Division & Manipulation
TypeDivision then Solve Polynomial Equation
DifficultyStandard +0.3 This is a slightly easier than average A-level question. Part (i) requires straightforward algebraic manipulation (equating the curves and multiplying through by x). Part (ii) uses the given root to factor the cubic via polynomial division, then solving the resulting quadratic—all standard C2 techniques with no novel insight required.
Spec1.02f Solve quadratic equations: including in a function of unknown1.02j Manipulate polynomials: expanding, factorising, division, factor theorem

4. \includegraphics[max width=\textwidth, alt={}, center]{30d4e6e5-8235-44b0-ad8e-c4c0b313677f-1_572_803_1336_461} The diagram shows the curves with equations \(y = 7 - 2 x - 3 x ^ { 2 }\) and \(y = \frac { 2 } { x }\).
The two curves intersect at the points \(P , Q\) and \(R\).
  1. Show that the \(x\)-coordinates of \(P , Q\) and \(R\) satisfy the equation $$3 x ^ { 3 } + 2 x ^ { 2 } - 7 x + 2 = 0$$ Given that \(P\) has coordinates \(( - 2 , - 1 )\),
  2. find the coordinates of \(Q\) and \(R\).

4.\\
\includegraphics[max width=\textwidth, alt={}, center]{30d4e6e5-8235-44b0-ad8e-c4c0b313677f-1_572_803_1336_461}

The diagram shows the curves with equations $y = 7 - 2 x - 3 x ^ { 2 }$ and $y = \frac { 2 } { x }$.\\
The two curves intersect at the points $P , Q$ and $R$.\\
(i) Show that the $x$-coordinates of $P , Q$ and $R$ satisfy the equation

$$3 x ^ { 3 } + 2 x ^ { 2 } - 7 x + 2 = 0$$

Given that $P$ has coordinates $( - 2 , - 1 )$,\\
(ii) find the coordinates of $Q$ and $R$.\\

\hfill \mbox{\textit{OCR C2  Q4 [8]}}