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΢·Ö·½³Ìxdy - 2ydx=0µÄͨ½âÊÇ?
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¡Ò(2ydx+2xdy)=?
¡ÓP(x,y)dx+Q(x,y)dy =¡Ò¡ÒD (∂Q/∂x -∂P/∂y)dxdy =¡Ò¡ÒD [d(2x)/dx-d(2y)/dy] dxdy =0 ËùÒÔ»ý·ÖÓë·¾¶Î޹أ¬Èç¹û...
ÇóY=¡Ò(2ydx+2xdy)
Y=2xy
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dy=x(2ydx - xdy)
dy=x(2ydx-xdy),(1+x^2)dy=2xydx,1/y *dy=2x/(1+x^2)*dxÉÏʽ»ý·ÖµÃ:lnIyI=ln(1+x^2)+lnC1,IyI=C1*(1+x^2),ÁîC=Õý¸ºC1,µÃͨ½âΪy=C*(1+x^...
2xdy +ydx=2©Rydy
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