Find the value of λ such that the line
is perpendicular to the plane 3x - y – 2z = 7.
Given :
Equation of line : ![]()
Equation of plane : 3x – y – 2z = 7
To Find : ![]()
Formulae :
1) Parallel vector to the line :
If equation of the line is
then,
Vector parallel to the line is given by,
![]()
2) Normal vector to the plane :
If equation of the plane is ax + by + cz = d then,
Vector normal to the plane is given by,
![]()
3) Cross Product :
If
are two vectors
![]()
![]()
then,

Answer :
For given equation of line,
![]()
Parallel vector to the line is
![]()
For given equation of plane,
3x – y – 2z = 7
normal vector to the plane is
![]()
As given line and plane are perpendicular to each other.
![]()

![]()
Comparing coefficients of
on both sides
![]()
3λ = -6
λ = -2