∑(n:0->∞) (n+1)/(2n+1)(n+1)/(2n+2) < (n+1)/(2n+1) 1/2 < (n+1)/(2n+1) (1)(n+1)/(2n+1) < (2n+1)/(2n+1) =1 (2)1/2 < (n+1)/(2n+1) < 1lim(n->∞) n/2 < ∑(n:0->∞) (n+1)/(2n+1) < lim(n->∞) n=>∑(n:0->∞) (n+1)/(2n+1) -> ∞