Inverse function of a two variable function

Click For Summary

Homework Help Overview

The discussion revolves around finding the inverse function of a two-variable function, specifically f(x,y). Participants are exploring the implications and requirements of defining such an inverse.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Some participants question the clarity of the original problem, asking whether the goal is to find the curve of (x,y) values for a specific constant c or something else. Others discuss the need to treat different cases based on the sign of y and the implications of mapping from a plane to a line.

Discussion Status

The discussion is ongoing, with participants seeking clarification from the original poster regarding the specifics of the question. There is recognition of the complexity involved in defining an inverse function in this context, and some participants suggest that the problem may not have a straightforward answer.

Contextual Notes

There is mention of the need to separate cases based on the sign of y and the challenge of mapping from the entire plane onto a line, which raises questions about the existence of such an inverse function.

misterau
Messages
20
Reaction score
0

Homework Statement


I'm wondering how to find the inverse function of some f(x,y)?

Homework Equations


The Attempt at a Solution

 
Last edited:
Physics news on Phys.org
misterau said:

Homework Statement


I wondering how to find the inverse function of some f(x,y)?

Homework Equations





The Attempt at a Solution


You need to define the question better. Do you want the curve of (x,y) values that give f(x,y) = c for some given c, or what? Typically, there will be many points, or no points, that give f(x,y) = c.
 
I need to show that f(x,y) = x/y has a right inverse that is a function f-1: R → R2 \ { (x,0) |x ∈ R} so that f . f-1(x) = x
 
The first, obvious, thing you will have to do is treat the sets {(x, y)|y> 0} and {(x, y)| y< 0} separately. For a given x, you want (u,v)= f^{-1}(u) such that u/v= x. Even requiring that v be positive, there area an infinite number of such pairs. The point is that your function, f, maps an entire plane onto the line (x, 0). The inverse function has to map that line onto the plane. No function can do that.
 
If the question as posted does not have an answer, let's let the OP, misterau, provide some clarification or correction.

misterau, please post the question in its exact words.
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
2K
Replies
13
Views
5K
  • · Replies 12 ·
Replies
12
Views
4K
  • · Replies 17 ·
Replies
17
Views
2K
  • · Replies 5 ·
Replies
5
Views
1K
  • · Replies 7 ·
Replies
7
Views
1K
  • · Replies 14 ·
Replies
14
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
Replies
2
Views
1K
  • · Replies 2 ·
Replies
2
Views
1K