Why did mathematicians conceptualized infinity? Do they use it in any mathematical systems?

Question

Why did mathematicians conceptualized infinity? Do they use it in any mathematical systems?

In: 13

Answer 1

Numerical analysts use an explicit infinity symbol in interval analysis. The idea is that each interval is represented by an upper bound and lower bound. Various arithmetic and set operations are defined for intervals.

Plus and minus infinity (and undefined) are defined with consistent properties.