Stable Type

A Polynomial equation whose Roots all have Negative Real Parts. For a Real Quadratic Equation

$$z^2+Bz+C=0,$$

the stability conditions are $B,C>0$. For a Real Cubic Equation

$$z^3+Az^2+Bz+C=0,$$

the stability conditions are $A,B,C>0$ and $AB>C$.

References

Birkhoff, G. and Mac Lane, S. A Survey of Modern Algebra, 3rd ed. New York: Macmillan, pp. 108-109, 1965.