2: The problem is of the type
∞ − ∞.
The leading term under the
root is n2, so when the root is taken into account, the
first term behaves like n when n goes to infinity, that is, it
is of the same order as the second term "-n".
In intuitive calculations the leading terms cancel out
![](gif3/eca3ab2.gif)
so we know that factoring out would not help.
Instead you would like to cancel n somehow. The best bet seems to be
getting rid of the square root algebraically, see the box
"difference of roots".
Next hint
Answer