Recent content by Fallen6

OK thank you all, I will correct my mistakes.

So fat this is what I got.

I donnot how to get the A and B value like A = ?, B = ?, and If I get the value of A and B, sub into general sol if it is equal to F sin wt then it is the final answer right?

I have no idea how to solve A and B, it is using the initial condition to solve for A and B ??

I feel sorry for my ignorant =.= So, I sub t into my general sol x = At cos wt + Bt cos wt x' = -Atw sin wt + A cos wt + Btw cos wt + B sin wt x'' = -Atw^2 cos wt + 2Bw cos wt - Btw^2 sin wt - 2Aw sin wt #After sub in equation I get 2Bw cos wt - 2Aw sin wt Am I wrong from the beginning...

I still can't get the answer..., can you show the answer with steps please??

Summary:: Initial value problem Solve the given initial-value problem differential equation by undetermined coefficient method. d^2 x/dt^2 + w^2 x = F sin wt , x(0) = 0, x'(0) = 0 I get the sol = C1 cos wt + C2 sin wt, but i always get 0 when I plug into the equation, anyone can help me...