This question causing me quite a few difficulties and I've got answer wrong so many times that I need help.
C4 Heinmann Book Mixed excercise 4F question 21
A population P is growing at a rate of 9% each year and at time t years may be approximiated by the formula:
P=P0(1.09)t Where t=>0 (t is greater then or equal to zero)
where P is regarded as a continuous function of t and P0 is the starting population at time t=0.
a) find an expression for t in terms of P and P0
Answer: (ln P-ln P0)/ln 1.09
b) Find the time T years when the population has doubled from its value at t=0 giving your answer to 3.s.f
Answer:8.04 years
c) Find, as a multiple of P0, the rate of change of population dP/dt at time t=T.
Answer: 0.172P0