Question

Qno.1) Establish the convergence or divergence of the sequence (Xn) such that
I) Xn= 1/1^2+1/2^2+1/3^2+.......1/n^2 for all n belongs to N.
ii) Xn= (1+1/n)^n+1 iii) Xn= (1+1/n+1)^n
Iv) Xn= (1-1/n)^n