we can try to transform this equation to exact differential equation by multiplying both side with integrating factor u(t) = exp( intergral of ((a-by^2)/(by^3+cy^2+ay)) dy ) ,  It's intagratable although it's hard with all these parameters.

[此贴子已经被作者于2007-11-7 5:31:44编辑过]

谢谢楼主