AQA FP3 2012 January — Question 4 10 marks

Exam BoardAQA
ModuleFP3 (Further Pure Mathematics 3)
Year2012
SessionJanuary
Marks10
PaperDownload PDF ↗
TopicFirst order differential equations (integrating factor)
TypeStandard linear first order - variable coefficients
DifficultyStandard +0.3 This is a standard integrating factor question from Further Maths with straightforward application of the method. Part (a) requires identifying the integrating factor μ = x², multiplying through, and integrating ∫x²ln(x)dx using integration by parts. Part (b) applies a boundary condition to find the constant. While it's Further Maths content and requires integration by parts, it follows a completely routine procedure with no conceptual challenges, making it slightly easier than average overall.
Spec4.10c Integrating factor: first order equations

4
  1. By using an integrating factor, find the general solution of the differential equation $$\frac { \mathrm { d } y } { \mathrm {~d} x } + \frac { 2 } { x } y = \ln x$$
  2. Hence, given that \(y \rightarrow 0\) as \(x \rightarrow 0\), find the value of \(y\) when \(x = 1\).

4
\begin{enumerate}[label=(\alph*)]
\item By using an integrating factor, find the general solution of the differential equation

$$\frac { \mathrm { d } y } { \mathrm {~d} x } + \frac { 2 } { x } y = \ln x$$
\item Hence, given that $y \rightarrow 0$ as $x \rightarrow 0$, find the value of $y$ when $x = 1$.
\end{enumerate}

\hfill \mbox{\textit{AQA FP3 2012 Q4 [10]}}