OCR C3 2009 January — Question 4 7 marks

Exam BoardOCR
ModuleC3 (Core Mathematics 3)
Year2009
SessionJanuary
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicProduct & Quotient Rules
TypeFind stationary points coordinates
DifficultyModerate -0.3 This is a straightforward application of chain rule (part i) and quotient rule (part ii) followed by solving dy/dx = 0. Both are standard textbook exercises with routine algebraic manipulation, making it slightly easier than average, though the quotient rule with ln x requires some care.
Spec1.07n Stationary points: find maxima, minima using derivatives1.07q Product and quotient rules: differentiation1.07r Chain rule: dy/dx = dy/du * du/dx and connected rates

4 For each of the following curves, find \(\frac { \mathrm { d } y } { \mathrm {~d} x }\) and determine the exact \(x\)-coordinate of the stationary point:
  1. \(y = \left( 4 x ^ { 2 } + 1 \right) ^ { 5 }\),
  2. \(y = \frac { x ^ { 2 } } { \ln x }\).

4 For each of the following curves, find $\frac { \mathrm { d } y } { \mathrm {~d} x }$ and determine the exact $x$-coordinate of the stationary point:\\
(i) $y = \left( 4 x ^ { 2 } + 1 \right) ^ { 5 }$,\\
(ii) $y = \frac { x ^ { 2 } } { \ln x }$.

\hfill \mbox{\textit{OCR C3 2009 Q4 [7]}}