Math Help - series question.

1. series question.

Hi, need help with this one: ImageShack - Image Hosting :: 65520560om6.jpg

it looks like an alternating series, which would need to eventually start decreasing and approach 0.

i thought about using the ratio test, or nth term test.

thanks for any help.

2. Apply Leibniz test. First prove the limit of the general term is zero, and prove that $a_n=\sqrt{n+1}-\sqrt n$ is a strictly decreasing sequence for $n>0.$