When an amount is described as being infinitesimal, it is equivalent to zero. This is because infinitesimal means infinitely minute... and the power of infinity is that instead of just being really, really, really minute, the scope is surpassed, and it’s not minute anymore but actually nonexistent! That is to say, 'infinitely minute' means more minute than the minimum minuteness. Since zero is equivalent to infinitesimality, zero is more similar to infinity than you might realize. Infinitesimality is just the inverse of infinity! If you find it hard to accept that infinitesimality is equivalent to zero, mathematics can actually can prove as much, in at least a couple of ways:

By demonstrating that an infinitesimal difference is none at all..

By simple logic..

infinitesimality is the inverse of infinity ⇒ infinitesimality = 1⁄∞ = 0