Jump to content

  • You cannot start a new topic
  • You cannot reply to this topic

nab recurrence relation question

catmandoo

Posted 16 October 2010 - 01:06 PM

the question- in a wood one fifth of the existing birds are killed by predators each year but during the nesting session 600 chicks are hatched . there are un birds at the start of a particular year

(a) write down a recurrence relation for un+1, the number of birds at the start of the next year
(b) find the limit of the sequence generated by this recurrence relation and explain what the limit means in the context of this question

PLEASE REPLY SOON IF U KNOW JUST IM STRUGGLING!!!!!!!!!!!!!!!!!!!!!!

Physics and Maths Tutor

Posted 16 October 2010 - 08:30 PM

View Postcatmandoo, on 16 October 2010 - 01:06 PM, said:

the question- in a wood one fifth of the existing birds are killed by predators each year but during the nesting session 600 chicks are hatched . there are un birds at the start of a particular year

(a) write down a recurrence relation for un+1, the number of birds at the start of the next year
(b) find the limit of the sequence generated by this recurrence relation and explain what the limit means in the context of this question

PLEASE REPLY SOON IF U KNOW JUST IM STRUGGLING!!!!!!!!!!!!!!!!!!!!!!

un+1 = mun + c
killed = 1/5 = 0.2
so, m = 0.8
c=600
a) un+1 = 0.8un + 600
b) L = c/(1-m) = 600/(1-0.8) = 600/0.2 = 3000
one fifth of 3000 =3000/5 = 600 (killed every year)
but 600 born every year

Physics & Maths Tutor
tutor@physics-maths.co.uk
www.physics-maths.co.uk
My link

catmandoo

Posted 17 October 2010 - 10:45 AM

thanks alot you made it look so easy cheers

  • You cannot start a new topic
  • You cannot reply to this topic