So I even asked a math tutor at school about this question and he had no idea

. I hope someone can help!

Does the sequence {[sigma] from n=1 to k ( 1/(k^2+n)^(1/2) )} k=1 to infinity.

I'm not sure how to do the symbols yet but its saying sigma from n=1 to k of 1 divided by the square root of k squared plus n and the whole thing goes from k=1 to infinity. this question stumped the math tutor so i hope someone can figure it out.

oh, and this was a hint given by the prof: C_k= [sigma] from n=1 to k ( 1/(k^2+n)^(1/2) ).............(k^2+1)^(1/2) <= (k^2+n)^(1/2) <= (k^2+k)^(1/2)......a_k<=c_k<=b_k

thanks!