Revision history [back]

It's apparently fixed in Sage 10.7.beta0

sage: B.<u,v> = AffineSpace(QQ,2)
....: p=Curve([2*u^2 + 2*u*v + 2*v^2 - 1],B)
....: p.rational_parameterization()
Scheme morphism:
From: Affine Space of dimension 1 over Number Field in a with defining polynomial a^2 - 2
To:   Affine Plane Curve over Number Field in a with defining polynomial a^2 - 2 defined by 2*u^2 + 2*u*v + 2*v^2 - 1
Defn: Defined on coordinates by sending (t) to
    ((-4*t^2 + 1)/((-4*a)*t^2 + (-2*a)*t + (-a)), (4*t^2 + 4*t)/((-4*a)*t^2 + (-2*a)*t + (-a)))
sage: