**? To put it very simply, it is a sum or series that has the following pattern:**

*Geometric Progression*Of course, you may then ask what is the sum to infinite terms, or the

**for this series, and we can then represent it as such:***sum to infinity*The previous post dealt with the problem of 0.11111… as a recurring decimal using the idea of a Geometric Progression, and I’m about to show you exactly how right now.

First of all, let us consider the

First of all, let us consider the

**(this is often called the***sum to n terms***):***partial sum of the first n terms*It must then be agreeable and logical that if I multiply this by the common ratio

*, I obtain:***r**Taking the difference of the two, I see that:

And rearranging, I immediately see that:

Now what is the sum to infinity then? Easy, it can be evaluated by considering the limit as

**tends towards infinity:***n*Notice that this limit can only exist, if the common ratio

**has a magnitude smaller than one, such that it decreases to effectively zero for huge values of**

*r***:**

*n*With this in mind, the sum to infinity is simply:

So applying this to the previous problem, we see that:

And therefore there is no actual need for any algebraic manipulation to solve for recurring numbers once you have grasped this theory. :)

## No comments:

Post a Comment