Question

The angle between the lines $\overrightarrow{r}=\hat{i}+4\hat{k}+\lambda(2\hat{i}+\hat{j}-\hat{k})$ and $\overrightarrow{r}=2\hat{i}-\hat{j}+3\hat{k}+\mu(3\hat{i}+\hat{k})$ is

• A. $\cos^{-1}(\frac{\sqrt{5}}{6})$
• B. $\cos^{-1}(\frac{\sqrt{15}}{6})$
• C. $\cos^{-1}(\frac{1}{12})$
• D. $\cos^{-1}(\frac{\sqrt{15}}{15})$
• E. $\cos^{-1}(\frac{\sqrt{3}}{30})$

Answer 1

Answer: (B)

$\cos^{-1}(\frac{\sqrt{15}}{6})$

Answer 2

The correct option is (B): $\cos^{-1}(\frac{\sqrt{15}}{6})$