1. ## Boundary Conditions

2. Originally Posted by signature
the method of undetermined coefficients should work nicely here. first find the homogeneous solution, then the particular solution using your initial conditions to solve for any arbitrary constants that may arise... am i helping here? you think you can start?

see post #6 in Chris' differential equations tutorial (link in my signature)

3. ## differential equations

Originally Posted by Jhevon
the method of undetermined coefficients should work nicely here. first find the homogeneous solution, then the particular solution using your initial conditions to solve for any arbitrary constants that may arise... am i helping here? you think you can start?

see post #6 in Chris' differential equations tutorial (link in my signature)
I tried using the xp = Atcos2t + Btsin2t + Ccos6t +Dsin6t

When i differentiated it twice, it gets really messy.

Can you please show me how it works.

4. Originally Posted by signature
I tried using the xp = Atcos2t + Btsin2t + Ccos6t +Dsin6t

When i differentiated it twice, it gets really messy.

Can you please show me how it works.
that is the correct choice. yes, it's going to be messy. note that you have to use the product rule to differentiate the first two terms. what did you end up with?