Edexcel FP2 — Question 44 14 marks

Exam BoardEdexcel
ModuleFP2 (Further Pure Mathematics 2)
Marks14
PaperDownload PDF ↗
TopicSecond order differential equations
TypeFind turning points or extrema
DifficultyStandard +0.3 This is a standard FP2 second-order differential equation question with auxiliary equation method, particular integral (polynomial form), and application of initial conditions. Part (c) requires finding a minimum using calculus, but all techniques are routine for Further Maths students. The question is methodical rather than requiring insight, making it slightly easier than average for A-level overall but typical for FP2.
Spec4.10b Model with differential equations: kinematics and other contexts4.10e Second order non-homogeneous: complementary + particular integral

  1. Find the general solution of the differential equation $$2\frac{d^2 x}{dt^2} + 5\frac{dx}{dt} + 2x = 2t + 9.$$ [6]
  2. Find the particular solution of this differential equation for which \(x = 3\) and \(\frac{dx}{dt} = -1\) when \(t = 0\). [4] The particular solution in part (b) is used to model the motion of a particle \(P\) on the \(x\)-axis. At time \(t\) seconds (\(t \geq 0\)), \(P\) is \(x\) metres from the origin \(O\).
  3. Show that the minimum distance between \(O\) and \(P\) is \(\frac{1}{2}(5 + \ln 2)\) m and justify that the distance is a minimum. [4]

\begin{enumerate}[label=(\alph*)]
\item Find the general solution of the differential equation
$$2\frac{d^2 x}{dt^2} + 5\frac{dx}{dt} + 2x = 2t + 9.$$ [6]

\item Find the particular solution of this differential equation for which $x = 3$ and $\frac{dx}{dt} = -1$ when $t = 0$. [4]

The particular solution in part (b) is used to model the motion of a particle $P$ on the $x$-axis. At time $t$ seconds ($t \geq 0$), $P$ is $x$ metres from the origin $O$.

\item Show that the minimum distance between $O$ and $P$ is $\frac{1}{2}(5 + \ln 2)$ m and justify that the distance is a minimum. [4]
\end{enumerate}

\hfill \mbox{\textit{Edexcel FP2  Q44 [14]}}