1)
\(\begin{array}{l}\hat{k}\end{array} \)
2)
\(\begin{array}{l}\hat{i}+\hat{j}\end{array} \)
3)
\(\begin{array}{l}\frac{\hat{i}+\hat{j}}{\sqrt{2}}\end{array} \)
4)
\(\begin{array}{l}\frac{\hat{i}+\hat{j}}{2}\end{array} \)
Answer: 3)
\(\begin{array}{l}\frac{\hat{i}+\hat{j}}{\sqrt{2}}\end{array} \)
Solution:
\(\begin{array}{l}\hat{R}=\frac{\vec{R}}{\left | R \right |}=\frac{\hat{i}+\hat{j}}{\sqrt{1^{2}+1^{2}}}= \frac{\hat{i}+\hat{j}}{\sqrt{2}}\end{array} \)
