OCR MEI C3 — Question 7 7 marks

Exam BoardOCR MEI
ModuleC3 (Core Mathematics 3)
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicChain Rule
TypeInverse function differentiation
DifficultyStandard +0.3 This question tests inverse trigonometric functions and implicit differentiation using dx/dy, which are standard C3 topics. Part (i) requires rearranging and differentiating (routine manipulation), while part (ii) needs substitution and exact value recall of cos(π/6). The multi-step nature and exact value requirement elevate it slightly above average, but it remains a straightforward application of taught techniques without requiring problem-solving insight.
Spec1.05i Inverse trig functions: arcsin, arccos, arctan domains and graphs1.07s Parametric and implicit differentiation

Fig. 3 shows the curve defined by the equation \(y = \arcsin(x - 1)\), for \(0 \leqslant x \leqslant 2\). \includegraphics{figure_7}
  1. Find \(x\) in terms of \(y\), and show that \(\frac{dx}{dy} = \cos y\). [3]
  2. Hence find the exact gradient of the curve at the point where \(x = 1.5\). [4]

Fig. 3 shows the curve defined by the equation $y = \arcsin(x - 1)$, for $0 \leqslant x \leqslant 2$.

\includegraphics{figure_7}

\begin{enumerate}[label=(\roman*)]
\item Find $x$ in terms of $y$, and show that $\frac{dx}{dy} = \cos y$. [3]

\item Hence find the exact gradient of the curve at the point where $x = 1.5$. [4]
\end{enumerate}

\hfill \mbox{\textit{OCR MEI C3  Q7 [7]}}