Chapter 13 - Vector Geometry - 13.5 Planes in 3-Space - Exercises - Page 684: 16

$\langle 1,0,0\rangle $

$ x=1$ can be rewritten as $1x+0y+0z=1$ The normal vector of a plane in the form $ ax+by+cz=d $ is $\vec n=\langle a,b,c\rangle $ Therefore, the normal vector of $1x+0y+0z=1$ is $\vec n=\langle 1,0,0\rangle $