Thank you sorry for the late reply, it was really just one question I was stuck on:
6. Initially the number of fish in a lake is 500 000. The population is then modelled by the recurrence
relation un + 1 = 1.05un – d, u0 = 500 000.
In this relation un is the number of fish in the lake after n years and d is the number of fish which
are caught each year.
Given that d = 15 000,
(a) calculate u1 , u2 and u3 and comment briefly on your results. (3)
Given that d = 100 000,
(b) show that the population of fish dies out during the sixth year. (3)
(c) Find the value of d which would leave the population each year unchanged. (2)
It was mainly part b which I thought was odd, I thought maybe I should just work out u1 u2 u3 untill u6 but that just seems like too much work for a c1 paper for 3 marks! Thank you for any help!