OCR MEI C1 2006 January — Question 12 13 marks

Exam BoardOCR MEI
ModuleC1 (Core Mathematics 1)
Year2006
SessionJanuary
Marks13
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicCurve Sketching
TypeSketch then solve related equations
DifficultyStandard +0.3 This is a straightforward C1 curve sketching question requiring expansion of brackets, factorization, and quadratic formula. While multi-part with 13 marks total, each step is routine: sketching a cubic from factored form, algebraic expansion, factor theorem application, and solving a quadratic. No novel insight required, just systematic application of standard techniques slightly above average difficulty due to length and surd manipulation.
Spec1.02j Manipulate polynomials: expanding, factorising, division, factor theorem1.02n Sketch curves: simple equations including polynomials

  1. Sketch the graph of \(y = x(x - 3)^2\). [3]
  2. Show that the equation \(x(x - 3)^2 = 2\) can be expressed as \(x^3 - 6x^2 + 9x - 2 = 0\). [2]
  3. Show that \(x = 2\) is one root of this equation and find the other two roots, expressing your answers in surd form. Show the location of these roots on your sketch graph in part (i). [8]

\begin{enumerate}[label=(\roman*)]
\item Sketch the graph of $y = x(x - 3)^2$. [3]

\item Show that the equation $x(x - 3)^2 = 2$ can be expressed as $x^3 - 6x^2 + 9x - 2 = 0$. [2]

\item Show that $x = 2$ is one root of this equation and find the other two roots, expressing your answers in surd form.

Show the location of these roots on your sketch graph in part (i). [8]
\end{enumerate}

\hfill \mbox{\textit{OCR MEI C1 2006 Q12 [13]}}