Tìm các giới hạn sau: b, lim (1- 1/ 2^2 ) ( 1- 1/3^2)...( 1- 1/n^2 )
Giải thích
b) Ta có 1−1221−1321−142...1−1n−121−1n2
=12.32.23.43.34.54...n−2n−1.nn−1.n−1n.n+1n=n+12n.
Suy ra lim1−1221−132...1−1n2=limn+12n=lim1+1n2=12.
b) Ta có 1−1221−1321−142...1−1n−121−1n2
=12.32.23.43.34.54...n−2n−1.nn−1.n−1n.n+1n=n+12n.
Suy ra lim1−1221−132...1−1n2=limn+12n=lim1+1n2=12.