Induktionsanfang: n = 1
∑(k = 1 bis 1) (k/(k + 1)!) = 1 - 1/(1 + 1)!
1/(1 + 1)! = 1 - 1/(1 + 1)!
1/2 = 1/2
stimmt!
Induktionsschritt: n --> n + 1
∑(k = 1 bis n + 1) (k/(k + 1)!) = 1 - 1/(n + 1 + 1)!
∑(k = 1 bis n) (k/(k + 1)!) + (n + 1)/((n + 1) + 1)! = 1 - 1/(n + 2)!
1 - 1/(n + 1)! + (n + 1)/(n + 2)! = 1 - 1/(n + 2)!
(n + 2)!/(n + 2)! - (n + 2)/(n + 2)! + (n + 1)/(n + 2)! = (n + 2)!/(n + 2)! - 1/(n + 2)!
(n + 2)! - (n + 2) + (n + 1) = (n + 2)! - 1
(n + 2)! - n - 2 + n + 1 = (n + 2)! - 1
(n + 2)! - 1 = (n + 2)! - 1
stimmt!