The question:

For small values of , how good is the approximation ?

By "small values", how small does the question want x to be? Less than 1? Less than 0.1? Less than 0.01?

Also, how do I proceed to get an approximation of the error? After expressing in terms of its Taylor series, at a point , I get the error term in terms of .

Any help to extend my reasoning would be much appreciated.