Answer
$7 ; \lt \dfrac{2}{7},\dfrac{-3}{7},\dfrac{6}{7}\gt$
Work Step by Step
As we know that the unit vector $\hat{\textbf{u}}$ is defined as: $\hat{\textbf{u}}=\dfrac{v}{|v|}$
Now, we have: Here, $|v|=\sqrt{(2)^2+(-3)^2+(6)^2}=\sqrt {49}=7$
Thus, $\hat{\textbf{u}}=\dfrac{v}{|v|}=\dfrac{\lt 2,-3,6 \gt}{7}= \lt \dfrac{2}{7},\dfrac{-3}{7},\dfrac{6}{7}\gt$
