Solving z*exp(z)=a: Proving Infinitely Many Roots

  • Thread starter bndnchrs
  • Start date
  • Tags
    Roots
In summary, the conversation discusses how to show that the equation z*exp(z) = a has infinitely many roots in the complex plane. The group cautions against using a series approach and suggests trying to solve it using norms of a ring. The Bob proposes writing out z as x + iy and finding infinitely many values that satisfy the equation.
  • #1
bndnchrs
29
0
This is not a homework problem, it is something that is stumping a group of us right now.

Show that

z*exp(z) = a

Has infinitely many roots in the complex plane.

I would caution against a series approach as we can't guarantee roots of the polynomial
z*exp(z) - a.

Any ideas?
 
Mathematics news on Phys.org
  • #2
Heya,

What is a? Either way, this is off the top of my head but you could try doing it via norms of a ring which would prehaps reduce it to an equation in the integers. I haven't even stopped to see if it will work but it is an idea :)

The Bob
 
  • #3
Write out z as x + iy and don't you soon see there are infinitely many values for which the real part of both sides is equal and infinitely many for which the imaginary part of both sides is equal, proving more than what you are asked?
 

Related to Solving z*exp(z)=a: Proving Infinitely Many Roots

What is the equation "z*exp(z)=a" used for?

The equation "z*exp(z)=a" is used to solve for the value of z that would make the expression equal to a given number, a. This type of equation is commonly used in mathematics and physics to find solutions for various problems.

What does it mean to have infinitely many roots for this equation?

Having infinitely many roots for this equation means that there are an infinite number of values of z that would satisfy the equation and make it equal to a. This is because the exponential function, exp(z), has an infinite number of values for different values of z.

How do you prove that there are infinitely many roots for this equation?

To prove that there are infinitely many roots for this equation, you can use the fundamental theorem of algebra which states that a polynomial of degree n has n complex roots. Since the equation "z*exp(z)=a" can be rewritten as a polynomial with infinite degree, it follows that there are infinitely many roots.

Can you provide an example of this equation with infinitely many roots?

One example of "z*exp(z)=a" with infinitely many roots is when a=0. In this case, the equation becomes z*exp(z)=0 which has an infinite number of solutions, including z=0 and z=-nπi, where n is any integer.

Are there any other methods to prove infinitely many roots for this equation?

Yes, there are other methods to prove infinitely many roots for this equation. One method is to use the intermediate value theorem, which states that if a continuous function takes on two different values at two points, then it must also take on every value in between. By applying this theorem to the equation "z*exp(z)=a", it can be shown that there are infinitely many values of z that would satisfy the equation and make it equal to a.

Similar threads

Replies
16
Views
2K
Replies
4
Views
473
Replies
2
Views
1K
  • Linear and Abstract Algebra
Replies
3
Views
1K
Replies
66
Views
4K
  • Precalculus Mathematics Homework Help
Replies
8
Views
1K
  • Precalculus Mathematics Homework Help
Replies
5
Views
887
  • Calculus and Beyond Homework Help
Replies
4
Views
1K
  • Quantum Interpretations and Foundations
Replies
1
Views
509
Replies
3
Views
2K
Back
Top