Question

If $\bar{a}=2\hat{i}+3\hat{j}-4\hat{k}$ and $\bar{b}=\hat{i}+3\hat{j}+2\hat{k}$, then a unit vector in the direction of $\bar a +\bar b$ is

• A. $\frac{1}{6}(3\hat{i}+6\hat{j}-2\hat{k})$
• B. $\frac{1}{\sqrt{70}}(3\hat{i}+6\hat{j}-5\hat{k})$
• C. $\frac{1}{7}(3\hat{i}+6\hat{j}-2\hat{k})$
• D. $\frac{1}{\sqrt{50}}(3\hat{i}+6\hat{j}-3\hat{k})$
• E. $\frac{1}{\sqrt{6}}(\hat{i}+2\hat{j}-\hat{k})$

Answer 1

Answer: (C)

$\frac{1}{7}(3\hat{i}+6\hat{j}-2\hat{k})$

Answer 2

The correct option is (C) : $\frac{1}{7}(3\hat{i}+6\hat{j}-2\hat{k})$