作者abcxyz123 (阿里八八与四十大盗)
看板Grad-ProbAsk
标题[理工] [工数]-级数解
时间Thu Nov 19 00:27:07 2009
(x^2-1)y''+xy'-y=0
级数解在整理系数时
(2n-3)(2n-5)....5x3x1 (2n-2)!
a2n= - ______________________ = - _______________________
(2n)(2n-2)......6x4x2 (2^2n-1)n!(n-1)!
↑2n表偶数
↑ 书直接写成这样
请问怎整理成这样的= =?
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