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#1 2008-02-09 11:10:13
- Mel
- Guest
Recursive sequences
Sequence: 1,3,11,43,171,683,2731
The sequence has a recursive formula of the form Tn= a(Tn-1)+b
(that should be a little n-1)
Find a and b
The answers are a=4 and b=-1 but i dont know how to get there
#2 2008-02-09 11:37:31
- JaneFairfax
- Member
- Registered: 2007-02-23
- Posts: 6,868
Re: Recursive sequences
Start with the first three terms. You have
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#3 2008-02-09 12:03:46
- Mel
- Guest
Re: Recursive sequences
Uhh then what? sorry im confused
#4 2008-02-09 12:19:37
- LuisRodg
- Real Member
- Registered: 2007-10-23
- Posts: 322
Re: Recursive sequences
Mel wrote:
Uhh then what? sorry im confused
Solve the system of equations and you get a = 4 and b = -1
EDIT:
Sorry didnt know you knew the answer already.
Ok so you have:
So solve for a:
Plug this in the other equation such that:
So now plug b into the first equation and u have a = 4.
Last edited by LuisRodg (2008-02-09 12:22:52)
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