Edexcel AEA 2002 June — Question 6 17 marks

Exam BoardEdexcel
ModuleAEA (Advanced Extension Award)
Year2002
SessionJune
Marks17
PaperDownload PDF ↗
TopicCurve Sketching
TypeArea between curve and line
DifficultyHard +2.3 This AEA question requires systematic analysis of curve properties (symmetry, intercepts), solving simultaneous Diophantine constraints, computing areas via integration with fractional powers, and finding gradient equality points. The multi-part structure demands sustained problem-solving across algebra, calculus, and optimization—significantly beyond standard A-level but accessible with careful reasoning.
Spec1.02n Sketch curves: simple equations including polynomials1.07i Differentiate x^n: for rational n and sums1.08e Area between curve and x-axis: using definite integrals

\includegraphics{figure_2} Figure 2 shows a sketch of part of two curves \(C_1\) and \(C_2\) for \(y \geq 0\). The equation of \(C_1\) is \(y = m_1 - x^{n_1}\) and the equation of \(C_2\) is \(y = m_2 - x^{n_2}\), where \(m_1\), \(m_2\), \(n_1\) and \(n_2\) are positive integers with \(m_2 > m_1\). Both \(C_1\) and \(C_2\) are symmetric about the line \(x = 0\) and they both pass through the points \((3, 0)\) and \((-3, 0)\). Given that \(n_1 + n_2 = 12\), find
  1. the possible values of \(n_1\) and \(n_2\), [4]
  2. the exact value of the smallest possible area between \(C_1\) and \(C_2\), simplifying your answer, [8]
  3. the largest value of \(x\) for which the gradients of the two curves can be the same. Leave your answer in surd form. [5]

\includegraphics{figure_2}

Figure 2 shows a sketch of part of two curves $C_1$ and $C_2$ for $y \geq 0$.

The equation of $C_1$ is $y = m_1 - x^{n_1}$ and the equation of $C_2$ is $y = m_2 - x^{n_2}$, where $m_1$, $m_2$, $n_1$ and $n_2$ are positive integers with $m_2 > m_1$.

Both $C_1$ and $C_2$ are symmetric about the line $x = 0$ and they both pass through the points $(3, 0)$ and $(-3, 0)$.

Given that $n_1 + n_2 = 12$, find

\begin{enumerate}[label=(\alph*)]
\item the possible values of $n_1$ and $n_2$,
[4]

\item the exact value of the smallest possible area between $C_1$ and $C_2$, simplifying your answer,
[8]

\item the largest value of $x$ for which the gradients of the two curves can be the same. Leave your answer in surd form.
[5]
\end{enumerate}

\hfill \mbox{\textit{Edexcel AEA 2002 Q6 [17]}}