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

It is used to calculate PI and some other numbers. An old method of calculating PI that is no longer used is to imagine a polygon inside a circle with all of the corners touching the circle. Calculating the circumference of a square gives a bad approximation of PI. An octagon gives a more accurate approximation. A 16 sided polygon is even more accurate. As the number if sides tends towards infinity, the approximation becomes more accurate. Isaac Newton found a better method using an infinite series that is easier to calculate.