A simple (nonrigorous) way to do it is to look at . When x is large, the 1 is so small as to be ignorable. ThusOriginally Posted by DangerMan
Depends on "how much rigour" you want...
You could always go back to the definition, but I wouldn't do that unless necessary.
Multiply numerator and denominator with the complement of the numerator to get:
Now the numerator is constant and positive and the denominator clearly goes to +infinity, yielding 0 as limit.