Let θ be the angle between the vectors a and b, where | a |=4,| b |=3 and θ ∈((π)/4, (π)/3). Then |( a - b ) ×( a + b )|^2+4( a · b )^2 is equal to \…

Let $\displaystyle \theta$ be the angle between the vectors $\displaystyle \overrightarrow{\mathrm{a}}$ and $\displaystyle \overrightarrow{\mathrm{b}}$, where $\displaystyle |\overrightarrow{\mathrm{a}}|=4,|\overrightarrow{\mathrm{~b}}|=3$ and $\displaystyle \theta \in\left(\frac{\pi}{4}, \frac{\pi}{3}\right)$. Then $\displaystyle |(\vec{a}-\vec{b}) \times(\vec{a}+\vec{b})|^2+4(\vec{a} \cdot \vec{b})^2$ is equal to \_\_\_\_.