Suppose for a_{n} >= 0 for all n and \sum_{n=1}^\infty a_n is convergent. explain why a_{n} < 1 for all large enough n.
Deduce that \sum_{n=1}^\infty \a_n^\2 is convergent.
Could anyone lend a hand? I know you have to use the comparison test, but how?
Thanks
I doubt we can help with what your lecturer has or has not done.
That is a matter for you to take up with your educational authority.
But you have a textbook/lecture notes. You can at least look up the what part of my question:
convergences only if what?
If you want more help, show some effort.