Edexcel FP2 — Question 8 15 marks

Exam BoardEdexcel
ModuleFP2 (Further Pure Mathematics 2)
Marks15
PaperDownload PDF ↗
TopicSecond order differential equations
TypeParticular solution with initial conditions
DifficultyStandard +0.8 This is a standard second-order linear ODE with constant coefficients requiring auxiliary equation solution, particular integral, and applying initial conditions (8 marks suggests multi-step work). Part (b) requires finding and justifying a maximum using calculus. While methodical, it's routine Further Maths material with no novel insight required, placing it moderately above average difficulty.
Spec4.10e Second order non-homogeneous: complementary + particular integral4.10f Simple harmonic motion: x'' = -omega^2 x

$$\frac{d^2 x}{dt^2} + 6 \frac{dx}{dt} + 6x = 2e^{-t}.$$ Given that \(x = 0\) and \(\frac{dx}{dt} = 2\) at \(t = 0\),
  1. find \(x\) in terms of \(t\). [8]
The solution to part (a) is used to represent the motion of a particle \(P\) on the \(x\)-axis. At time \(t\) seconds, where \(t > 0\), \(P\) is \(x\) metres from the origin \(O\).
  1. Show that the maximum distance between \(O\) and \(P\) is \(\frac{2\sqrt{3}}{9}\) m and justify that this distance is a maximum. [7]

$$\frac{d^2 x}{dt^2} + 6 \frac{dx}{dt} + 6x = 2e^{-t}.$$

Given that $x = 0$ and $\frac{dx}{dt} = 2$ at $t = 0$,

\begin{enumerate}[label=(\alph*)]
\item find $x$ in terms of $t$. [8]
\end{enumerate}

The solution to part (a) is used to represent the motion of a particle $P$ on the $x$-axis. At time $t$ seconds, where $t > 0$, $P$ is $x$ metres from the origin $O$.

\begin{enumerate}[label=(\alph*)]
\setcounter{enumi}{1}
\item Show that the maximum distance between $O$ and $P$ is $\frac{2\sqrt{3}}{9}$ m and justify that this distance is a maximum. [7]
\end{enumerate}

\hfill \mbox{\textit{Edexcel FP2  Q8 [15]}}