AQA C4 2013 January — Question 5 9 marks

Exam BoardAQA
ModuleC4 (Core Mathematics 4)
Year2013
SessionJanuary
Marks9
PaperDownload PDF ↗
TopicIntegration by Substitution
TypeFinding curve equation from derivative
DifficultyStandard +0.3 Part (a) is a standard integration by substitution with u = x² + 3, requiring recognition of the derivative pattern. Part (b) is a separable differential equation requiring routine separation of variables, integration of both sides using part (a), and application of initial conditions. This is a typical C4 question testing standard techniques with no novel insight required, making it slightly easier than average.
Spec1.08h Integration by substitution1.08k Separable differential equations: dy/dx = f(x)g(y)

5
  1. Find \(\int x \sqrt { x ^ { 2 } + 3 } \mathrm {~d} x\).
    (2 marks)
  2. Solve the differential equation $$\frac { \mathrm { d } y } { \mathrm {~d} x } = \frac { x \sqrt { x ^ { 2 } + 3 } } { \mathrm { e } ^ { 2 y } }$$ given that \(y = 0\) when \(x = 1\). Give your answer in the form \(y = \mathrm { f } ( x )\).

5
\begin{enumerate}[label=(\alph*)]
\item Find $\int x \sqrt { x ^ { 2 } + 3 } \mathrm {~d} x$.\\
(2 marks)
\item Solve the differential equation

$$\frac { \mathrm { d } y } { \mathrm {~d} x } = \frac { x \sqrt { x ^ { 2 } + 3 } } { \mathrm { e } ^ { 2 y } }$$

given that $y = 0$ when $x = 1$. Give your answer in the form $y = \mathrm { f } ( x )$.
\end{enumerate}

\hfill \mbox{\textit{AQA C4 2013 Q5 [9]}}