Question

Hi folks, I solved a 2nd order DE to obtain the general solution:
y = A cos2x + B sin2x - (1/5) sin3x
When I apply the two boundary conditions:
y(-pi) = y(pi) and y'(-pi) = y'(pi) I get:
A = A and B = B, what does this mean and have I applied the boundary conditions correctly??

Answer 1

yes for the first one I get A=A. when you get the same thing on both sides I believe that means A can be any constant

let me look at the second one...

Answer 2

Thanks..

Answer 3

same thing for the second one
i get B=B
same case here B can be any constant

Answer 4

Cheers, so having assertained that A and B are constants, how would I write that as an answer? Would I just write the general solution and say that A and B are constants???

Answer 5

yes thats what i would do

Answer 6

but any solution of that form is a solution

Answer 7

Excellent, thankyou :-)