Question
Vectors $\vec{a}$ and $\vec{b}$ are inclined at an angle $\theta = 60^\circ$. If $|\vec{a}| = 1$ and $|\vec{b}| = 2$, then $[(\vec{a} + 3\vec{b}) \times (3\vec{a} - \vec{b})]^2$ is equal to
Vectors $\vec{a}$ and $\vec{b}$ are inclined at an angle $\theta = 60^\circ$. If $|\vec{a}| = 1$ and $|\vec{b}| = 2$, then $[(\vec{a} + 3\vec{b}) \times (3\vec{a} - \vec{b})]^2$ is equal to