In order to obtain the algebraic equation of a limit cycle, the following equations are available:F(x, x) = F(x, x) F(x, x) = -F(-x, x) we may use the algebraic equation of limit cycle to check the accuracy of approximate numerical computation.

• 为了便于求出极限环的代数方程,下列两式是很有用的。 F(x,x)=F(x,-x) F(x,x)=-F(-x,x)我们可将所求得的极限环的代数方程去校核近似数值计算的精确程度。