Adding infinitesimals

[robvalue]

You're welcome

Calculus has a lot to do with limits of things approaching zero, both for differentiating and integrating.

For example, differentiating a function is done by [lim h tend to 0 ]( (f(x+h) - f(x)) / h )

You're calculating a tangent at a particular point by taking an approximate tangent extremely close by at the point x+h, and then allowing h to shrink right down to zero.

Maths has always been one of my passions!