Question

The angle between the two vectors $\overrightarrow{A}=3\hat{i}+4\hat{j}+5\hat{k}$ and $\overrightarrow{B}=3\hat{i}+4\hat{j}+5\hat{k}$ is

• A. ${60}^{\circ }$
• B. Zero
• C. ${90}^{\circ }$
• D. None of these

Answer 1

The correct option is D None of these

$cos\theta =\frac{\overrightarrow{A}.\overrightarrow{B}}{|A||B|}=\frac{9+16+25}{\sqrt{9+16+25}\sqrt{9+16+25}}=\frac{50}{50}=1$
$\Rightarrow cos\theta =1\therefore \theta =co{s}^{-1}\left(1\right)$