limn→∞[1
limn→∞[1-2+3-4+...+(2n-1)]/[根号下(n^2+1) +根号下(n^2-1)limn→∞[1-2+3-4+...+(2n-1)]/[根号下(n^2+1) +根号下(n^2-1)]的值是
原式=limn→∞[1+3+5+...+(2n+1)-2-4-6-...-2n]/[根号下(n^2+1) +根号下(n^2-1)] =limn→∞[(1+2n+1)*(2n+1)/2-(2+2n)*2n/2)]/[根号下(n^2+1) +根号下(n^2-1)] =limn→∞(n+1)/[根号下(n^2+1)+根号下(n^2-1)] =limn→∞(1+1/n)/[根号下(1+1/n^2)+根号下(1-1/n^2)] =limn→∞ 1/(1+1) =1/2
答:设Bn=2/3*4/5*…*2n/(2n+1), 则0<An<Bn, ∴An^2<An*Bn=1/(2n+1), ∴An<1/√(2n+1), ∴当n→+∞时A...详情>>