设y= (1+1/2)(1+1/4)……(1+1/2^n)
=2(1-1/2)(1+1/2)(1+1/4)……(1+1/2^n)
=2(1-1/4)(1+1/4)……(1+1/2^n)
=2(1-1/2^2n)
所以lim (1+1/2)(1+1/4)……(1+1/2^n) (n→∞时)
=2
设y= (1+1/2)(1+1/4)……(1+1/2^n)
=2(1-1/2)(1+1/2)(1+1/4)……(1+1/2^n)
=2(1-1/4)(1+1/4)……(1+1/2^n)
=2(1-1/2^2n)
所以lim (1+1/2)(1+1/4)……(1+1/2^n) (n→∞时)
=2