Are the Cauchy-Riemann Equations Ever Satisfied for f(z) = |z|?

  • Thread starter Thread starter icystrike
  • Start date Start date
  • Tags Tags
    Cauchy Riemann
Click For Summary
The discussion centers on the Cauchy-Riemann equations and their applicability to the function f(z) = |z|, which is defined as f(z) = √(x² + y²). It is stated that the Cauchy-Riemann equations are not satisfied when x and y are both non-zero, as well as at the origin where x = y = 0. The participants are tasked with expressing f(z) in terms of its real and imaginary components, u(x,y) and v(x,y), and computing the necessary derivatives. The conversation emphasizes the conditions under which the Cauchy-Riemann equations hold true for this specific function. Ultimately, the conclusion is that f(z) = |z| does not meet the criteria established by the Cauchy-Riemann equations.
icystrike
Messages
444
Reaction score
1

Homework Statement


What does it mean by this:
The cauchy riemann equations are never satisfied when x and y are different from zero and when x=y=0 .

Looking at the example of f(z)= l z l = \sqrt{x^{2}+y^{2}}

Homework Equations





The Attempt at a Solution

 
Physics news on Phys.org
write f(z)=u(x,y)+iv(x,y) and compute the derivatives, when are the CR equations satisfied?
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

Similar threads

  • · Replies 11 ·
Replies
11
Views
3K
  • · Replies 19 ·
Replies
19
Views
2K
  • · Replies 27 ·
Replies
27
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 16 ·
Replies
16
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 5 ·
Replies
5
Views
5K
Replies
7
Views
2K
Replies
4
Views
2K