AQA C3 2011 June — Question 2 9 marks

Exam BoardAQA
ModuleC3 (Core Mathematics 3)
Year2011
SessionJune
Marks9
PaperDownload PDF ↗
TopicProduct & Quotient Rules
TypeFind derivative of composite quotient/product
DifficultyModerate -0.3 This is a straightforward differentiation question testing standard techniques (product rule, quotient rule, and tangent line equation). Part (a) is routine product rule application, part (b) is standard tangent finding, and part (c) is guided quotient rule with algebraic simplification using a trigonometric identity. All techniques are core C3 material with no novel problem-solving required, making it slightly easier than average.
Spec1.07m Tangents and normals: gradient and equations1.07q Product and quotient rules: differentiation1.07r Chain rule: dy/dx = dy/du * du/dx and connected rates

    1. Find \(\frac{dy}{dx}\) when \(y = xe^{2x}\). [3]
    2. Find an equation of the tangent to the curve \(y = xe^{2x}\) at the point \((1, e^2)\). [2]
  1. Given that \(y = \frac{2\sin 3x}{1 + \cos 3x}\), use the quotient rule to show that $$\frac{dy}{dx} = \frac{k}{1 + \cos 3x}$$ where \(k\) is an integer. [4]

\begin{enumerate}[label=(\alph*)]
\item \begin{enumerate}[label=(\roman*)]
\item Find $\frac{dy}{dx}$ when $y = xe^{2x}$. [3]

\item Find an equation of the tangent to the curve $y = xe^{2x}$ at the point $(1, e^2)$. [2]
\end{enumerate}

\item Given that $y = \frac{2\sin 3x}{1 + \cos 3x}$, use the quotient rule to show that
$$\frac{dy}{dx} = \frac{k}{1 + \cos 3x}$$
where $k$ is an integer. [4]
\end{enumerate}

\hfill \mbox{\textit{AQA C3 2011 Q2 [9]}}