Hi, I have a problem in which, given a polynomial, I have to calculate the number of roots with positive, zero and/or negative real parts. Now I know that every sign change in the first column of the Routh array indicates the number of roots with a positive real part, but how do I find out the roots with negative and/or zero real parts? I've tried reading up on it, but couldn't find the answer to this anywhere. Any help would be appreciated. Thanks!