mersenneforum.org (https://www.mersenneforum.org/index.php)
-   Homework Help (https://www.mersenneforum.org/forumdisplay.php?f=78)

 wildrabbitt 2020-01-30 09:31

infinite products

I've got a maths degree but I was never taught about infinite products. I'd like to ask something : when do people [I]usually[/I] learn about infinite products?

I suppose it must be at masters level but then there are different masters degrees, so perhaps it's in a particular branch of maths (maybe analytic number theory) ?

 R. Gerbicz 2020-01-30 09:55

[QUOTE=wildrabbitt;536233]I've got a maths degree but I was never taught about infinite products. I'd like to ask something : when do people [I]usually[/I] learn about infinite products?
[/QUOTE]

With proper education you can learn that first at high school.

 Nick 2020-01-30 10:37

[QUOTE=wildrabbitt;536233]when do people [I]usually[/I] learn about infinite products?[/QUOTE]
Here in the Netherlands, we teach infinite products and direct sums (of various mathematical structures) in the 2nd year of the 3 year university bachelor in mathematics.

 pinhodecarlos 2020-01-30 10:38

[QUOTE=R. Gerbicz;536234]With proper education you can learn that first at high school.[/QUOTE]

Here at nursery level.

 CRGreathouse 2020-01-30 14:24

[QUOTE=R. Gerbicz;536234]With proper education you can learn that first at high school.[/QUOTE]

It's a part of calculus, so in high school or early in college I think.

 M344587487 2020-01-30 14:54

In the UK it's at A levels but different exam boards might not have it on the curriculum, there's at least 3 popular exam boards. The majority of my first year at uni was recapping A levels in a bit more depth to get everyone up to same level, it's a very wasteful system that could do with an overhaul.

 Dr Sardonicus 2020-01-30 16:35

You need to know about convergence, and most likely natural logarithms also. (Convergence of an infinite product is often equated to convergence of the series of natural logs of (all but finitely many of) the factors, assuming a branch of the log for which ln(1) is 0.

So probably first semester calculus at earliest -- late HS or early college.

You might not run into infinite products until you take complex analysis. That would be a bit later. An amusing example is

$$\prod_{n=0}^{\infty}(1\;+\;z^{2^{n}})$$

which converges for |z| < 1. Premultiply by 1 - z and watch what happens :smile:

 wildrabbitt 2020-02-03 16:04

Merci.

Merci beaucoup docteur. Quelque choses a faire maintenant.

 ricardos 2020-02-11 13:00

Thank you. It's very useful and smart definition.

 All times are UTC. The time now is 08:28.