The ratio as n gets larger is aid to approach the Golden ratio, which is approximately equal to 1.618. What happens to the inverse of this ratio, ? What number does this quantity approach? How does this compare to the original ratio?
Answers
Answer:
The limit of the ratios of the consecutive Fibonacci terms as n tends to infinity is the golden number φ . The inverse of this ratio is 1/φ which equals to φ−1 .
Proof:
We will employ Binet’s formula from which we know that:
φ=(5–√+1)/2…(1)
ψ=(1−5–√)/2…(2)
Lim[Fn+1/Fn]=
[(φn+1−ψn+1)/5–√]/[(φn−ψn)/5–√]=
Lim[(φn+1−ψn+1)]/[(φn−ψn)]…(3)
We divide numerator and denominator by φn and we take:
Lim[(φn+1−ψn+1)]/[(φn−ψn)]=
Lim[(φ−[(1−5–√)/(1+5–√)]n)((1−5–√)/2)]/[1−[(1−5–√)/(1+5–√)]n]=
Lim[(φ−0)/(1–0)]=φ
Proof that 1/φ=φ−1 :
1/φ=1/[(5–√+1)/2]=2/(5–√+1)=
2(5–√−1)/[(5–√+1)(5–√−1)]=
2(5–√−1)/(5−1)=(5–√−1)/2=
(5–√+1−2)/2=(5–√+1)/2−2/2=φ−1
The same happens with the Lucas sequence and with any Generalized Fibonacci sequence.
Step-by-step explanation: