Matrices & Determinants · Evaluation of determinants

Among the statements:

I: If $\begin{vmatrix} 1 & \cos\alpha & \cos\beta\\ \cos\alpha & 1 & \cos\gamma\\ \cos\beta & \cos\gamma & 1\end{vmatrix} = \begin{vmatrix} 0 & \cos\alpha & \cos\beta\\ \cos\alpha & 0 & \cos\gamma\\ \cos\beta & \cos\gamma & 0\end{vmatrix}$, then $\cos^2\alpha + \cos^2\beta + \cos^2\gamma = \dfrac32$, and

II: If $\begin{vmatrix} x^2 + x & x + 1 & x - 2\\ 2x^2 + 3x - 1 & 3x & 3x - 3\\ x^2 + 2x + 3 & 2x - 1 & 2x - 1\end{vmatrix} = px + q$, then $p^2 = 196q^2$,