Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

Pages: **1**

**Bishmay****Member**- Registered: 2013-02-14
- Posts: 2

Check for analyticity: f(z)= 1/(1-z^4)

Please show the steps... Should I start with z= x+iy or take rcoso +i sino????

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 83,159

Hi;

Aren't rational functions analytic away from their poles?

**In mathematics, you don't understand things. You just get used to them.I have the result, but I do not yet know how to get it.All physicists, and a good many quite respectable mathematicians are contemptuous about proof.**

Offline

**Bishmay****Member**- Registered: 2013-02-14
- Posts: 2

Hi,

The complex function is given and it is asked to check whether it is analytic or not... But I am confused how to proceed

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 83,159

Hi;

Your poles are

1, -1, i, -i

A rational function is analytic at each point of its domain. Does that help a bit? What is the domain of your function?

*Last edited by bobbym (2013-02-14 09:27:34)*

**In mathematics, you don't understand things. You just get used to them.I have the result, but I do not yet know how to get it.All physicists, and a good many quite respectable mathematicians are contemptuous about proof.**

Offline

Pages: **1**