Find the vector equation of the plane through the points (2, 1, – 1) and (– 1, 3, 4) and perpendicular to the plane
x – 2y + 4z = 10.
Vector equation of a plane is given as
Where is any point on the plane and
is a vector perpendicular to the plane.
Now, the given plane x – 2y + 4z = 10 is perpendicular to required plane. So, the normal vector of x – 2y + 4z = 10 will be parallel to the required plane. Hence, is parallel to the required plane.
Points say A(2,1, – 1) and B(– 1,3,4) are on the plane hence the vector is also parallel to the required plane so,
is parallel to the required plane.
Hence as both and
are parallel to the plane so the direction of
is the cross product of the two vectors.
So, the equation of required plane is,
Hence, the vector equation of required plane is
.