作者a016258 (莫名其妙)
看板Grad-ProbAsk
标题Re: [理工] [工数]-一阶ODE
时间Thu Jul 23 18:53:05 2009
: xyy'=2y^2+4x^2
: y(xdy-2ydx)=4x^2dx
: 接下来你会的......
=>
-2
y d( x y )
------------- = 4x^2 dx
x^(-3)
-2 -1
y d ( x y ) = 4 * x dx
-2 -2 -3
x y d ( x y ) = 4 * x dx
1 -4 2 -2
----- x y = - 2 x + c
2
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