Another Differential Equations Problem

  • #1

Homework Statement


For what values of K does the function y=cos k t satisft the differential equation 4y"=-25y?



Do I have to find the derivative of y twice or what do i do
 

Answers and Replies

  • #2
1,753
1
... what does y'' mean?
 
  • #3
it means second order derivative I believe
 
  • #4
737
0
Yes, find the second derivative and compare constants.
 
  • #5
ok so it would be y"=-k^2cos kt
 
  • #6
737
0
Yes.
 
  • #7
then do i plug in values for it
 
  • #8
Gib Z
Homework Helper
3,346
6
You have 4y"=-25y. Substitute what you know to be y and y'', and equate coefficients as Tedjn said.
 

Related Threads on Another Differential Equations Problem

Replies
2
Views
2K
  • Last Post
Replies
3
Views
806
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
1
Views
919
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
4
Views
2K
  • Last Post
Replies
2
Views
1K
  • Last Post
Replies
7
Views
1K
  • Last Post
Replies
4
Views
1K
  • Last Post
Replies
2
Views
1K
Top