/sci/ - Science & Math

1/e^(-infinity) = e^infinity, not 0.

E^{-\infty} = 0 not \infty

> What did I do wrong here?
You are treating infinity like an actual number.

>>5309295
That's also true, but that's not the problem.

DRAW A GRAPH!!!!

much easier to conceptualize

For the last fucking time, infinity is a concept, NOT a number.

And the concept of a limit does not reduce to "plug in the thing the arrow is pointing at.

Now that a look at the graph of y(x) = e^-x.

What happens when x approaches minus infinity (or infinitely far "left" on a Cartesian graph)? The function grows to infinity, that's closer the concept of a limit, it's not an algebraic solution.

>>5309304

>implying Numbers aren't concepts

>>5309304
>infinity is a concept, NOT a number.
lol tell that to Cantor

>>5309298
No that is the problem, >>5309289 >>5309290 is incorrect.

>>5309308
>>Durrr two different concepts are the same thing hurr

>>5309308
> cats are mammals, not dogs
> durrp implying dogs are not mammals

Let's see... technically infinity is equal to zero at some point, but it's also every number larger than that. So you're not wrong, but you only found one of infinite solutions. Though this statement itself is probably wrong.

>>5309316
Why would I tell him something that he already understands?

>>5309304
>implying OP isnt using a much less formal casting of infinity that works for his purpose

Deal with it, formalists.

>>5309308
All things are concepts. What he meant was numbers a concept involving objects, whereas infinity is a concept involving a specific case of said objects.

>>5309328
Ah, but it DIDN'T work did it?

On the right side, your second to third step is wrong
e^(-inf) would come out to e^(inf), negative exponents inverse the coefficient etc etc
so, e^(inf) = e^(inf)

>>5309334
eg: 4^(-x) = 1/(4^x)
and 1/4^(-x) = 4^(x)

>>5309333
No, he fucked it up because he is retarded. Do you really think he would do better using delta-eplison?

>>5309345

Sorry. I'm tired and just realized that it indeed is.

Also, why the fuck is a phone number in my Catchpa

>>5309290

This is correct.

>>5309352
A fair point, but using a limit like OP could lead to many, many mistakes that could be avoided, especially when you need to prove convergence of series'. Also with the idea of inf as a number you'd have a tougher time imagining things like Fourier series' (I've experienced students making some really odd suggestions) etc.

circle has 0 sides.. circle has infinite sides

0 = infinity in a lot of circumstances, its mainly about how you conceptualize it