I am trying to determine constraints for a,b,c that are real, such that the eigenvalues of my system matrix have all negative real part.
If all eigenvalues real part must be less than 0, then clearly:
c < 0
ab < 1
However, when trying to verify these results with "is" and "coulditbe" Maple gives me blatantly false results:
The real part of -1+sqrt(a*b) can never be greater than 0 under the assumption that ab<1. So why is Maple giving me nonsense? Am I using the commands incorrectly?