Answer
$\dfrac{3 \sqrt 2}{2}\approx 2.12$
Work Step by Step
Write the parametric equations:
$x=1+t; y=2-t; z=-1+2t$
$\implies 1(1+t) -1(2-t) +2(-1+2t) =0$
$\implies 1+t-2+t-2+4t=0$
$\implies 6t-3=0$
$\implies t=\dfrac{1}{2}$
The distance formula is given by:
$Distance=\sqrt {(\dfrac{3}{2}-0)^2 +(\dfrac{3}{2}-0)^2 +(0-0)^2 }=\sqrt {\dfrac{9}{2}}$
So, $Distance=\dfrac{3 \sqrt 2}{2}\approx 2.12$
