Re: [理工] [工數]-ODE~~~~~~~~~~~~~~~~~~~~~~

看板Grad-ProbAsk作者CRAZYAWIND (怒火燒不盡)時間16年前 (2010/02/11 14:38)推噓2(2推 0噓 1→)

留言3則, 2人參與討論串2/2 (看更多)

※ 引述《osunriceo (語)》之銘言： : xy'' + 2y' - xy = 2expx : ans: y = (A exp(-x) + B expx )/x + expx : plz hel~ 2 因為Q - 1/2P' - 1/4P = -1 令y = uv ∫-1/x dx u=e = 1/x x v" -v = 2e x -x vh = c1e + c2e 1 x vp = ────── 2e (D+1)(D-1) x = xe x -x x v = c1e +c2e +xe x -x x y = uv = (c1e +c2e )/x +e -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 218.163.40.185

推

osunriceo

02/11 20:12, , 1^F

02/11 20:12, 1^F

→

CRAZYAWIND

02/11 20:19, , 2^F

02/11 20:19, 2^F

推

osunriceo

02/11 20:37, , 3^F

02/11 20:37, 3^F