1. The problem statement, all variables and given/known data Solve DE:y' + 2ty = 5t 3. The attempt at a solution For yh: y' + 2ty = 0 y' = -2ty Thus int(y-1,y) = int(-2t,t) ln(y) = -t2 + C1 y = e-t2 + C1 = eC1e-t2 = Ce-t2 To find yp there are two ways to do it. With an integrating factor exp(-A(t)) where A'(t) = 2t or by saying yp = v(t)yh(t). Both ways will result in int(e-t2,t) which is unsolvable. So I checked up the answer which read 5/2 + Cet2, so yp(t)=5/2. So I checked it by entering 5/2 in the DE and of course it was right. Now my question is, how would you arrive at that answer? When would you make the assumption yp' = 0 and check if it is right? Isn't that too trivial? And when you would find an answer for yp' = 0, would you stop searching for another answer?