OCR H240/02 — Question 2 7 marks

Exam BoardOCR
ModuleH240/02 (Pure Mathematics and Statistics)
Marks7
PaperDownload PDF ↗
TopicTangents, normals and gradients
TypeDetermine nature of stationary points
DifficultyModerate -0.8 This is a straightforward application of basic differentiation rules (power rule) and standard stationary point analysis. All parts are routine: differentiate twice, substitute x=4 to verify dy/dx=0, then use the second derivative test. No problem-solving insight required, just mechanical application of standard techniques.
Spec1.07d Second derivatives: d^2y/dx^2 notation1.07i Differentiate x^n: for rational n and sums1.07n Stationary points: find maxima, minima using derivatives1.07o Increasing/decreasing: functions using sign of dy/dx

2 A curve has equation \(y = x ^ { 5 } - 5 x ^ { 4 }\).
  1. Find \(\frac { \mathrm { d } y } { \mathrm {~d} x }\) and \(\frac { \mathrm { d } ^ { 2 } y } { \mathrm {~d} x ^ { 2 } }\).
  2. Verify that the curve has a stationary point when \(x = 4\).
  3. Determine the nature of this stationary point.

2 A curve has equation $y = x ^ { 5 } - 5 x ^ { 4 }$.
\begin{enumerate}[label=(\alph*)]
\item Find $\frac { \mathrm { d } y } { \mathrm {~d} x }$ and $\frac { \mathrm { d } ^ { 2 } y } { \mathrm {~d} x ^ { 2 } }$.
\item Verify that the curve has a stationary point when $x = 4$.
\item Determine the nature of this stationary point.
\end{enumerate}

\hfill \mbox{\textit{OCR H240/02  Q2 [7]}}