Answer
$\sqrt 2$
Work Step by Step
The formula to calculate the distance for two vectors is given by:
$d=\dfrac{|u \cdot v|}{|v|}$
Thus, we have $u \cdot v=-2(1)+(0)(-1)+6(0)=-2$
and $|u \cdot v|=|-2|=2$
Now, $d=\dfrac{|u \cdot v|}{|v|}=\dfrac{2}{ \sqrt {(1)^2+(-1)^2+(0)^2}}=\dfrac{2}{\sqrt {2}}=\sqrt 2$
