Multiply polynomials
We can multiply polynomials by using single point evaluation and then reconstruction with genpoly.
> poly1 := 2*x^4+x^3+7*x^2+8*x+6;
> poly2 := 3*x^4+5*x^3+9*x^2+4*x+3;
> value1 := subs(x=1000,poly1);
> value2 := subs(x=1000,poly2);
> v12 := value1*value2;
> ans := sort(genpoly(v12,1000,x));
Check with expand
> p12 := expand(poly1*poly2);
> zero3 := p12-ans;