n→∞
lim ln((1+1/n)(1+2/n)……(1+n/n))^(2/n)
=lim 2(1/n)[ln(1+1/n)+ln(1+2/n)+……+ln(1+n/n)]
=2∫²₁lnxdx
=2x(lnx-1)|²₁
=4(ln2-1)-2(ln1-1)
=4ln2-2
n→∞
lim ln((1+1/n)(1+2/n)……(1+n/n))^(2/n)
=lim 2(1/n)[ln(1+1/n)+ln(1+2/n)+……+ln(1+n/n)]
=2∫²₁lnxdx
=2x(lnx-1)|²₁
=4(ln2-1)-2(ln1-1)
=4ln2-2