【摘要】 <正> 对于三次曲线: AX~3+3BX~2Y+3CXY~2+DY~3+3EX~2+6FXY+3GY~2+HX+IY+K=0文[1]借助于初等变换将其化为下面四种形式:更多还原

【Abstract】 In this paper, we discuss the cubic system with cubic curve solution xy~2=ax~3+bx~2+cx(a<0, b≠0), give out the general form of this system, prove that if the curve has a closed branch, then the closed branch may be limit cycle. We also give out the sufficient conditions of closed branch being a unique limit cycle, prove the system, when closed branch is a limit cycle, may possess another limit cycles.更多还原