Which of these is the Binet formula for the nnn-th Fibonacci number FnF_nFn?
Fn=ϕn−(1−ϕ)n5F_n = \frac{\phi^n - (1-\phi)^n}{\sqrt{5}}Fn=5ϕn−(1−ϕ)n
Fn=ϕn+(1−ϕ)n2F_n = \frac{\phi^n + (1-\phi)^n}{2}Fn=2ϕn+(1−ϕ)n
Fn=ϕn−ψn2F_n = \frac{\phi^n - \psi^n}{2}Fn=2ϕn−ψn
Fn=ϕn+ψnF_n = \phi^n + \psi^nFn=ϕn+ψn