Question

Need help with dot product

Answer 1

$\textbf{A}\cdot\textbf{B} = 11.5$

Explanation:

The dot product between two vectors $\textbf{A}$ and $\textbf{B}$ is defined as

$\textbf{A}\cdot\textbf{B} = AB\cos{\theta}$

where A and B are the magnitudes of the vectors $\textbf{A}$ and $\textbf{B},$ respectively and $\theta$ is the angle between the two. Since A = 3, B = 5 and $\theta = 40°,$ the dot product $\textbf{A}\cdot\textbf{B}$ is

$\textbf{A}\cdot\textbf{B} = (3)(5)(0.766) = 11.5$