SPS
SPS FM Pure
2023
September
Q8
7 marks
Standard +0.8
A population of meerkats is being studied.
The population is modelled by the differential equation
$$\frac{\mathrm{d}P}{\mathrm{d}t} = \frac{1}{22}P(11 - 2P), \quad t \geq 0, \quad 0 < P < 5.5$$
where \(P\), in thousands, is the population of meerkats and \(t\) is the time measured in years since the study began.
Given that there were 1000 meerkats in the population when the study began, determine the time taken, in years, for this population of meerkats to double. [7]
SPS
SPS FM Pure
2024
February
Q5
6 marks
Standard +0.8
The sequence \(u_1, u_2, u_3, \ldots\) is defined by
$$u_1 = 0 \quad u_{n+1} = \frac{5}{6 - u_n}$$
Prove by induction that, for all integers \(n \geq 1\),
$$u_n = \frac{5^n - 5}{5^n - 1}$$ [6 marks]