Chapter 11 - Section 11.5 - Lines and Planes in Space - Exercises - Page 631: 35

$0$

The formula to calculate the distance for two vectors is given by: $d=\dfrac{|u \times v|}{|v|}$ Thus, we have $u \times v=\lt 0,0,0\gt $ and $|u \times v|=\sqrt{(0)^2+(0)^2+(0)^2}=0$ Now, $d=\dfrac{|u \times v|}{|v|}=\dfrac{0}{2 \sqrt {10}}=0$