Prove that $f$ is a diffeomorphism $C^∞$, that maps... (More inside)
Prove that $f:(x, y) ∈ R^2$ - {(0, 0)} → ($\frac{x}{x^2 +y^2} $ ; $\frac{y}{x^2+y^2} $) ∈ $R^2$ - {(0, 0)} is a diffeomorphism $C^∞$, that maps each circle of radius $r > 0$ centered in the origin to a cocentric circle with radius $\frac{1}{r} $ .
Answer
Answers can only be viewed under the following conditions:
- The questioner was satisfied with and accepted the answer, or
- The answer was evaluated as being 100% correct by the judge.
1 Attachment

4.8K
-
Hey, just one question, I don't really understand how that last part proves the last argument (that f maps each circle of radius r > 0 centered in the origin to a concentric circle with radius 1/r). Would you be able to clarify that?
-
Note that if |(x,y)| =s, then |f(x,y)|=|(u,v)|=1/s. When s varies between (0,r), 1/s covers (1/r, infinity). I hope this helps.
The answer is accepted.
Join Matchmaticians Affiliate Marketing
Program to earn up to a 50% commission on every question that your affiliated users ask or answer.
- answered
- 926 views
- $10.00
Related Questions
- Use Green’s theorem to compute $\int_C x^2 ydx − xy^2 dy$ where $C$ is the circle $x^2 + y ^2 = 4$ oriented counter-clockwise.
- Two exercises in complex analysis
- Double Integrals, polar coordinates, Stoke's theorem, and Flow line Questions
- Finding the arc length of a path between two points
- How to derive the term acting like a first derivative with respect to A that I found by accident?
- Gauss's Theorem
- Use Green’s theorem to evaluate the line integral $\int_C (1+xy^2)dx-x^2ydy$ on the arc of a parabola
- Does $\sum_{n=2}^{\infty}\frac{\sin n}{n \ln n}$ converge or diverge?