D-resultant and subresultants
D-resultant and subresultants
We establish a connection between the D-resultant of two polynomials $f(t)$ and $g(t)$ and the subresultant sequence of $f(t)-x$ and $g(t)-y$. This connection is used to decide in a more explicit way whether $\mathcal {K}(f(t),g(t))=\mathcal {K}(t)$ or $\mathcal {K}[f(t),g(t)]=\mathcal {K}[t]$. We also show how to extract a faithful parametrization from …