Where " p " denotes the maximum number of positive roots, " q " denotes the maximum number of negative roots ( both of which can be found using Descartes'rule of signs ), and " n " denotes the degree of the equation.
12.
When the coefficients a _ 1 and a _ 2 are both zero no information can be obtained about the location of the roots, because not all roots are real ( as can be seen from Descartes'rule of signs ) unless the constant term is also zero.
