If the Wronskian equals 0, is it always 0?

  • Thread starter TheCanadian
  • Start date
  • Tags
    Wronskian
In summary, the Wronskian of a set of equations can be equal to 0 over one interval in the functions' domain, but non-zero over another interval, indicating linear dependence and independence respectively. This is demonstrated by the example of three functions in "Advanced Engineering Mathematics", 3rd Ed., by Erwin Kreyszig.
  • #1
TheCanadian
367
13
If the Wronskian of a set of equations equals 0 over a particular interval in the functions' domain, is it possible for it be non-zero under another interval? Are there any particular proofs for or against this?
 
Mathematics news on Phys.org
  • #2
TheCanadian said:
If the Wronskian of a set of equations equals 0 over a particular interval in the functions' domain, is it possible for it be non-zero under another interval? Are there any particular proofs for or against this?
It took me a very long while to find a good example, but I found one in, of all places, "Advanced Engineering Mathematics", 3rd Ed., by Erwin Kreyszig.
Consider the three functions: ##y_1 = x^3, y_2 = |x|^3, y_3 = 1##.
##W(y_1, y_2, y_3)## is identically zero on one interval (implying that the three functions are linearly dependent on that interval), but ##W(y_1, y_2, y_3)## is different from zero on another interval (implying that the three functions are linearly independent on that other interval). I leave it to you to figure out what intervals we're talking about here.
 
  • Like
Likes TheCanadian
  • #3
Mark44 said:
It took me a very long while to find a good example, but I found one in, of all places, "Advanced Engineering Mathematics", 3rd Ed., by Erwin Kreyszig.
Consider the three functions: ##y_1 = x^3, y_2 = |x|^3, y_3 = 1##.
##W(y_1, y_2, y_3)## is identically zero on one interval (implying that the three functions are linearly dependent on that interval), but ##W(y_1, y_2, y_3)## is different from zero on another interval (implying that the three functions are linearly independent on that other interval). I leave it to you to figure out what intervals we're talking about here.

Thank you! :D
 

1. What is the Wronskian?

The Wronskian is a mathematical concept used in differential equations to determine whether a set of functions is linearly independent or dependent.

2. What does it mean if the Wronskian equals 0?

If the Wronskian equals 0, it means that the set of functions is linearly dependent, which means that one function can be expressed as a linear combination of the other functions in the set.

3. Is the Wronskian always 0?

No, the Wronskian is not always 0. It can only be 0 if the set of functions is linearly dependent.

4. Can the Wronskian be negative or positive?

Yes, the Wronskian can be negative, positive, or 0. It is dependent on the specific set of functions being evaluated.

5. What is the significance of the Wronskian being 0?

If the Wronskian is 0, it indicates that the set of functions is not a fundamental set of solutions for a given differential equation. This means that the solutions to the differential equation may not be unique and further analysis is needed.

Similar threads

  • Calculus and Beyond Homework Help
Replies
2
Views
293
  • Calculus and Beyond Homework Help
Replies
1
Views
304
  • Differential Equations
Replies
1
Views
1K
Replies
1
Views
2K
  • Calculus and Beyond Homework Help
Replies
7
Views
2K
  • Calculus and Beyond Homework Help
Replies
7
Views
715
  • Linear and Abstract Algebra
Replies
3
Views
1K
  • Calculus and Beyond Homework Help
Replies
19
Views
3K
  • Calculus and Beyond Homework Help
Replies
11
Views
2K
  • Differential Equations
Replies
2
Views
1K
Back
Top