Math Is Fun Forum

gourish

Member

Registered: 2013-05-28

Posts: 153

Fibonacci sequence

here is a question that i came across in a competition (math crusade 2014) which i couldn't answer

Q.) if the nth term of the Fibonacci sequence: 1,1,2,3,5,8,13..... is represented by Fn then for n greater then 4 and being a composite number
prove that Fn is a composite number

if you guys can show me the way i can walk the path.... like how should prove that a given number is composite when i cannot even have any idea of what it's factors may be...

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"The man was just too bored so he invented maths for fun"
-some wise guy

Agnishom

Real Member

From: Riemann Sphere

Registered: 2011-01-29

Posts: 24,974

Website

Re: Fibonacci sequence

Look up Binet's formula

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'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.

gourish

Member

Registered: 2013-05-28

Posts: 153

Re: Fibonacci sequence

still couldn't solve the problem... can you show me how to prove it?

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"The man was just too bored so he invented maths for fun"
-some wise guy