CountRoots

CountRoots[poly,x]
gives the number of real roots of the polynomial poly in x.

CountRoots[poly,{x,a,b}]
gives the number of roots between a and b.

DetailsDetails

  • CountRoots enumerates roots with multiplicities counted.
  • Roots that lie exactly at or are counted.
  • The limits a and b can be complex, in which case the range is taken to be a closed rectangle in the complex plane.
Introduced in 2007
(6.0)