Let \( |\vec{a}|=2 \), \( |\vec{b}|=3 \) and the angle between the vectors \( \vec{a} \) and \( \vec{b} \) be \( \dfrac{\pi}{4} \). Then \( \left|(\vec{a}+2\vec{b})\times(2\vec{a}-3\vec{b})\right|^{2} \) is equal to:
\( 882 \)
\( 441 \)
\( 841 \)
\( 482 \)