特征为2的域上的双线性型

hbghlyj

在linmultialg中说

different quadratic forms like $x^2 +xy$ and $xy$ can have the same symmetric bilinear form,
and some symmetric bilinear forms like $xx' + yy'$ do not arise as the bilinear form of any quadratic form.

这两句话怎么证明呢

hbghlyj

沉贴了