2-torsion
= 2-torsion
{title2=$E[2]$}
On a Weierstrass equation $y^2=f(x)$ in characteristic other than two, the nonidentity 2-torsion points are exactly $(r,0)$ for the roots $r$ of $f$.
= 2-torsion
{title2=$E[2]$}
On a Weierstrass equation $y^2=f(x)$ in characteristic other than two, the nonidentity 2-torsion points are exactly $(r,0)$ for the roots $r$ of $f$.