编辑: admin 2017-26-02
let
f(x) = 2 - 1/(1+x)
f'(x) = 1/(1+x)^2 > 0
xn 是单调上升
|xn| < 2
lim(n-> ∞) xn = L
x(n+1) = 2- 1/(1+xn)
L = 2 - 1/(1+L)
L^2 + L = 1+2L
L^2 - L+1 = 0
L = (1+√5)/2