need some help with this problem
a. Show that, whatever is the whole number, k is superior or equal to 2;
1/k^2 is less than or equal to 1/ k-1 - 1/ K
Have done this and think I have the answer but part 2 and 3 are complicated
b. Use this result to show the inequality
€ ----- is less than or equal to
c. Show that (Un) which is defined by Un=€ .1...
k=2 K^2 is convergent
Thanks in advance for any hints to proceed...