方程y'^3+2xy'-y=0的通解
1个回答

∵令y'=p,则代入原方程得y=p³+2xp.(1)

==>p=3p²p'+2p+2xp' (两端对x求导数)

==>3p²dp+2xdp+pdx=0

==>3p³dp+2xpdp+p²dx=0 (两端同乘p)

==>3d(p^4)+4d(xp²)=0

==>3p^4+4xp²=C (C是积分常数)

==>x=C/p²-3p²

==>y=2C/p-5p³

∴原方程的通解参数形式是x=C/p²-3p²,y=2C/p-5p³ (C是积分常数,p是参数).