# Math Help - Fibonacci sequence

1. ## Fibonacci sequence

Hi can anyone explain how i can get express Fn+3 in terms of Fn+2 and Fn to show that Fn+2 = 1/2(Fn+3 + Fn). Any help is much appreciated

2. ## Re: Fibonacci sequence

I would begin with:

(1) $F_{n+2}=F_{n+1}+F_{n}$

(2) $F_{n+3}=F_{n+2}+F_{n+1}$

Now, solve (2) for $F_{n+1}$ and substitute into (1), then solve for $F_{n+2}$.

3. ## Re: Fibonacci sequence

Thankyou so much.