The Infinitesimal
The infinitesimal , simply put, is just a function or variable that tends (approaches) zero.
Think about this function again:
As x tends to either infinity, you have now learned that 1/x tends to zero.
If x is an infinite, then obviously, f(x) is an infinitesimal.
You can connect a lot of these concepts together to have a much easier time calculating limits.
To properly connect everything we've discussed so far, we'll head into The Algebra of Limits