Re: [工數] 請教一題改寫微分方程的問題

[ntust661 (一千個傷心的理由)]

※ 引述《janelin319 (小人)》之銘言：
: 有一題題目是
: 將一個三階線性微分方程式y'''-4y"-8y'-10y=cost
: 改寫三個一階線性微分方程式
: 請問什麼意思??請教版上前輩教教我> <


  y = x1


  y' = x2 = x1'


  y'' = x3 = x2'


  y''' = x3'


  y''' - 4 y'' - 8y' - 10y = cost = x3' - 4x3 - 8x2 - 10x1



     [ x1 ]   [ 0  1  0 ][ x1 ]   [   0  ]
  d  [    ]   [         ][    ]   [      ]
── [ x2 ] = [ 0  0  1 ][ x2 ] + [   0  ]
 dt  [    ]   [         ][    ]   [      ]
     [ x3 ]   [10  8  4 ][ x3 ]   [ cost ]



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