1. ## glb and lub

How can I find the glb and lub of:

(n^2+17n)^1/2 -(n^2+8n)^1/2

Thanks

Sorry, dont know if these are standard abbreviations but i mean greatest lower bound and least upper bound

2. (n^2+17n)^1/2 -(n^2+8n)^1/2 obtains its global minimum at n=-17

to find the lub, find the limit as n goes to infinity.