Question

If the angle between the vectors $\overrightarrow{A}$ and $\overrightarrow{B}$ is $\theta ,$ the value of the product $(\overrightarrow{B}\times \overrightarrow{A})\cdot \overrightarrow{A}$ is equal to

• A. $B{A}^2\cos \theta$
• B. $B{A}^2\sin \theta$
• C. $B{A}^2\sin \theta \cos \theta$
• D. Zero

Answer 1

The correct option is D Zero

$\overrightarrow{B}\times \overrightarrow{A}$ is always perpendicular to both $\overrightarrow{A}$ and $\overrightarrow{B}$. Thus, the dot product of this cross product with $\overrightarrow{A}$ will be zero.