作者osunriceo (语)
看板Grad-ProbAsk
标题[理工] [工数]-ODE~~~~~~~~~~~~~~~~~~~~~~
时间Thu Feb 11 14:10:32 2010
xy'' + 2y' - xy = 2expx
ans: y = (A exp(-x) + B expx )/x + expx
plz hel~
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1F：→ r19891011:(xy)"-xy=2e^x 感觉一下=> y=(ae^x +be^-x)/x+e^x 02/11 14:41
2F：推 Dola1003:应变数变更 特解u=exp x 另y=uv 可以解出来~ 02/18 00:56