OCR MEI C3 2010 January — Question 3 7 marks

Exam BoardOCR MEI
ModuleC3 (Core Mathematics 3)
Year2010
SessionJanuary
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicChain Rule
TypeImplicit differentiation
DifficultyModerate -0.3 This is a straightforward application of the chain rule and implicit differentiation with standard functions. Part (i) is routine differentiation of a composite function, and part (ii) applies implicit differentiation to a simple equation then verifies equivalence by substitution—both are textbook exercises requiring no problem-solving insight, making it slightly easier than average.
Spec1.07r Chain rule: dy/dx = dy/du * du/dx and connected rates1.07s Parametric and implicit differentiation

3
  1. Given that \(y = \sqrt [ 3 ] { 1 + 3 x ^ { 2 } }\), use the chain rule to find \(\frac { \mathrm { d } y } { \mathrm {~d} x }\) in terms of \(x\).
  2. Given that \(y ^ { 3 } = 1 + 3 x ^ { 2 }\), use implicit differentiation to find \(\frac { \mathrm { d } y } { \mathrm {~d} x }\) in terms of \(x\) and \(y\). Show that this result is equivalent to the result in part (i).

3 (i) Given that $y = \sqrt [ 3 ] { 1 + 3 x ^ { 2 } }$, use the chain rule to find $\frac { \mathrm { d } y } { \mathrm {~d} x }$ in terms of $x$.\\
(ii) Given that $y ^ { 3 } = 1 + 3 x ^ { 2 }$, use implicit differentiation to find $\frac { \mathrm { d } y } { \mathrm {~d} x }$ in terms of $x$ and $y$. Show that this result is equivalent to the result in part (i).

\hfill \mbox{\textit{OCR MEI C3 2010 Q3 [7]}}