Answer
$3$
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 $u \cdot v=-1(-1)+(-2)(-4)+(-2)(0)=9$
and $|u \cdot v|=|9|=9$
Now, $d=\dfrac{|u \cdot v|}{|v|}=\dfrac{9}{ \sqrt {(-1)^2+(-2)^2+(-2)^2}}=\dfrac{9}{3}=3$
