# Help stuck on PDE problem

1. Oct 1, 2009

### mike1111

1. The problem statement, all variables and given/known data
Use Fourier transforms to get solution in terms of f(t) adn g(t)

2. Relevant equations
d4u + K2*d2u =0
dx4 (space) dt2

u(0,t)=f(t)
u'(0,t)=g(t)
u''(L,t)=0
u'''(L,t)=0

3. The attempt at a solution
I been working no it for hours the best I got is
k4U +K* (d2U/dt2) =0
I'm not sure where to go since i dont hve initial conditions

Really need someone to show me how to do the question or a similiar one

Last edited: Oct 1, 2009
2. Oct 1, 2009

### HallsofIvy

Staff Emeritus
Yes, you do have initial conditions! They are u(x,0)= f(t) and u'(x,0)= g(t). (I assume the ' denotes differentiation with respect to t.)

3. Oct 1, 2009

### mike1111

my fault, there aren't meant to be initial ocnidtion, just fixed the question