lim_(n->unendlich) (1 + 2 + · · · + n)/n² | oben: arithmetische Summe (Reihe)
= lim_(n->unendlich) (n/2 * (n+1))/n^2
= lim_(n->unendlich) (n^2 + n)/(2n^2)
= lim_(n->unendlich) (n^2/n^2 + n/n^2)/(2n^2/n^2)
= lim_(n->unendlich) (1 + 1/n)/(2)
= (1+0)/2
= 1/2