Dimostrazione.
1.
$q(\lambda \mathbf{v})= f(\lambda \mathbf{v},\lambda \mathbf{v})= \lambda f(\mat...

...lambda \mathbf{v})= \lambda^{2}f(\mathbf{v},\mathbf{v})= \lambda q(\mathbf{v}).$
2.
$q(\mathbf{v}+\mathbf{w})= f(\mathbf{v}+\mathbf{w},\mathbf{v}+\mathbf{w})= f(\ma...

...(\mathbf{w}+\mathbf{w})= q(\mathbf{v})+2f(\mathbf{v},\mathbf{w})+q(\mathbf{w}).$
c.v.d.