OCR MEI C2 2010 June — Question 3 5 marks

Exam BoardOCR MEI
ModuleC2 (Core Mathematics 2)
Year2010
SessionJune
Marks5
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicTangents, normals and gradients
TypeFind stationary points
DifficultyModerate -0.8 This is a straightforward two-part question requiring basic differentiation using the power rule, then solving a simple quadratic equation (dy/dx = 0) to find stationary points. Both are routine C2-level techniques with no problem-solving insight required, making it easier than average but not trivial since it requires correct execution of multiple steps.
Spec1.07i Differentiate x^n: for rational n and sums1.07n Stationary points: find maxima, minima using derivatives

  1. Differentiate \(x^3 - 6x^2 - 15x + 50\). [2]
  2. Hence find the \(x\)-coordinates of the stationary points on the curve \(y = x^3 - 6x^2 - 15x + 50\). [3]

(i)
AnswerMarks Guidance
\(3x^2 - 12x - 15\)2 marks M1 if one term incorrect or an extra term is included
(ii)
AnswerMarks
Their \(\frac{dv}{dx} = 0\) s.o.i.M1
\(x = 5\)B1
\(x = -1\)B1
## (i)
$3x^2 - 12x - 15$ | 2 marks | M1 if one term incorrect or an extra term is included

## (ii)
Their $\frac{dv}{dx} = 0$ s.o.i. | M1 | 
$x = 5$ | B1 | 
$x = -1$ | B1 |
\begin{enumerate}[label=(\roman*)]
\item Differentiate $x^3 - 6x^2 - 15x + 50$. [2]

\item Hence find the $x$-coordinates of the stationary points on the curve $y = x^3 - 6x^2 - 15x + 50$. [3]
\end{enumerate}

\hfill \mbox{\textit{OCR MEI C2 2010 Q3 [5]}}