Just have an observation;

If you take the numbers they are taking, [1, 2, 3, 4], than 2S2 ==> 1 -2 + 1 + 3 - 2 - 4 + 3 - 4 This is exactly what they are saying in the video.

The result of this is not 1/4,as you can see but

- 4. BUT they are using infinity. Therefore, here is where I got confuse. Since they are moving aside the second serie (to get the 1 - 1 + 1 ... ), it also shift the last number no? Therefore the last number must be moved aside too.

Example: if you go until 10, then your serie will be -10. And so forth until infinity. If the serie will go until 1, then the result will be 11.

In consequence, the last number is either + or - infinity.

S2 = + or - infinity.Then, we know that

S - S2 = 4SSo S = -S2/3If S2 = + infinity then the result is negative and will not have any sense.

But if S2 = - infinity than

S = + infinity, which make a bit more sense!

Please tell me what to think about this, and if I am wrong, where did my logic is wrong!

Thanks for this video again!

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