Find a vector equation of the plane that is perpendicular tothe x-axis and contains the point P(1, 1, 3).
A vector equation of the plane is given by the point P(1,1,3), and then two vectors in the plane. Any two vectors will do, we can use the vectors (0,1,0) and (0,0,1), since those are both in the yz plane.
The vector equation of the plane then becomes
`(x, y, z)=(1,1,3)+s(0,1,0)+t(0,0,1)` where s and t are parameters.