A note on the discriminant

Abstract

Let $F(X,Y)=Y^d+a_1(X)Y^{d-1}+...+a_d(X)$ be a polynomial in $n+1$ variables $(X,Y)=(X_1,...,X_n,Y)$ with coefficients in an algebraically closed field K. Assuming that the discriminant $D(X)=\disc_Y F(X,Y)$ is nonzero we investigate the order $\ord_P D$ for $P\in K^n$. As application we get a discriminant criterion for the hypersurface F=0 to be nonsingular.