Q.
Let $\left|\vec{A}_{1}\right| =3, \left|\vec{A}_{2}\right| = 5 $ and $\left|\vec{A}_{1} +\vec{A_{2}}\right| = 5$
The value of $ \left(2 \vec{A}_{1} + 3\vec{A}_{2}\right). \left(3\vec{A}_{1} - 2\vec{A}_{2}\right) $ is : -
Solution: