• Support PF! Buy your school textbooks, materials and every day products Here!

Proving the expectation value of any eigenvalue function

  • #1
295
4

Homework Statement


upload_2017-3-18_15-37-43.png


Homework Equations


upload_2017-3-18_15-38-16.png

upload_2017-3-18_15-40-42.png


The Attempt at a Solution


When I take the second formula, multiply by it's conjugate and then by x and do the integral of the first formula, I get 0, and not L/2, for <x>. Am I missing a formula ?
The complex conjugate of the exponential part multiplied by the exponential part simplifies to 1, and when I do the integral I end up with 0.
 

Answers and Replies

  • #2
kuruman
Science Advisor
Homework Helper
Insights Author
Gold Member
9,037
2,424
What are your integration limits?
 
  • #3
295
4
What are your integration limits?
-infinity and +infinity, as in the first formula (the orange background)
 
  • #4
kuruman
Science Advisor
Homework Helper
Insights Author
Gold Member
9,037
2,424
What is the size of the "box" the particle is in?
 
  • #5
295
4
What is the size of the "box" the particle is in?
L? so would it be from 0 to L ?
 
  • #6
kuruman
Science Advisor
Homework Helper
Insights Author
Gold Member
9,037
2,424
Right. The particle is confined from 0 to L.
 

Related Threads on Proving the expectation value of any eigenvalue function

  • Last Post
Replies
2
Views
1K
  • Last Post
Replies
4
Views
2K
  • Last Post
Replies
2
Views
7K
  • Last Post
Replies
2
Views
3K
  • Last Post
Replies
2
Views
3K
  • Last Post
Replies
0
Views
4K
  • Last Post
Replies
1
Views
7K
Replies
18
Views
3K
Replies
5
Views
684
Replies
8
Views
1K
Top