OCR MEI C3 2011 June — Question 9 18 marks

Exam BoardOCR MEI
ModuleC3 (Core Mathematics 3)
Year2011
SessionJune
Marks18
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicComposite & Inverse Functions
TypeFind inverse function
DifficultyStandard +0.3 This is a structured multi-part question covering standard C3 techniques (finding constants from graphs, differentiation, inverse functions, integration). Part (i) requires reading values from a graph; part (ii) involves routine differentiation and showing a maximum using calculus; part (iii) requires finding an inverse function with domain/range and using the inverse function gradient relationship; part (iv) is straightforward integration. All parts follow textbook methods with no novel insight required, making it slightly easier than average.
Spec1.02v Inverse and composite functions: graphs and conditions for existence1.05f Trigonometric function graphs: symmetries and periodicities1.08d Evaluate definite integrals: between limits

Fig. 9 shows the curve \(y = f(x)\). The endpoints of the curve are P \((-\pi, 1)\) and Q \((\pi, 3)\), and \(f(x) = a + \sin bx\), where \(a\) and \(b\) are constants. \includegraphics{figure_9}
  1. Using Fig. 9, show that \(a = 2\) and \(b = \frac{1}{2}\). [3]
  2. Find the gradient of the curve \(y = f(x)\) at the point \((0, 2)\). Show that there is no point on the curve at which the gradient is greater than this. [5]
  3. Find \(f^{-1}(x)\), and state its domain and range. Write down the gradient of \(y = f^{-1}(x)\) at the point \((2, 0)\). [6]
  4. Find the area enclosed by the curve \(y = f(x)\), the \(x\)-axis, the \(y\)-axis and the line \(x = \pi\). [4]

Fig. 9 shows the curve $y = f(x)$. The endpoints of the curve are P $(-\pi, 1)$ and Q $(\pi, 3)$, and $f(x) = a + \sin bx$, where $a$ and $b$ are constants.

\includegraphics{figure_9}

\begin{enumerate}[label=(\roman*)]
\item Using Fig. 9, show that $a = 2$ and $b = \frac{1}{2}$. [3]

\item Find the gradient of the curve $y = f(x)$ at the point $(0, 2)$.

Show that there is no point on the curve at which the gradient is greater than this. [5]

\item Find $f^{-1}(x)$, and state its domain and range.

Write down the gradient of $y = f^{-1}(x)$ at the point $(2, 0)$. [6]

\item Find the area enclosed by the curve $y = f(x)$, the $x$-axis, the $y$-axis and the line $x = \pi$. [4]
\end{enumerate}

\hfill \mbox{\textit{OCR MEI C3 2011 Q9 [18]}}