- #1
saxen
- 44
- 0
Homework Statement
u[itex]_{t}[/itex]=3u[itex]_{xx}[/itex] x=[0,pi]
u(0,t)=u(pi,t)=0
u(x,0)=sinx*cos4x
Homework Equations
The Attempt at a Solution
with separation of variables and boundry conditions I get:
u(x,t)= [itex]\sum[/itex]B[itex]_{n}[/itex]e[itex]^-3n^{2)}}*sinnx[/itex]
u(x,0)=sinx*cos4x
f(x)=sinx*cos4x=[itex]\sum[/itex]B[itex]_{n}*sinnx[/itex]
And here is where I am stuck! I tried computing B[itex]_{n} by computing it like a Fourier coeff. of f(x) but all I got was zero... I don't really know where to go from here.
I'm having a hard time with Fourier analysis, that's why I have bombarded this forums with question these last couple of days. I really appreciate the help I get.