JEE Advanced2012MathematicsThree Dimensional GeometryActual
If the straight lines x-1 2 = y+1 k = z 2 and x+1 5 = y+1 2 = z k are coplanar, then the plane (s) containing these two lines is (are)
Options
- Ay+2 z=-1
- By+z=-1
- Cy-z=-1
- Dy-2 z=-1
Correct answer
B. y+z=-1
Step-by-step solution
Given that lines are coplanar. | array ccc x₂-x₁ & y₂-y₁ & z₂-z₁ a₁ & b₁ & c₁ a₂ & b₂ & c₂ array |= | array ccc 2 & 0 & 0 2 & k & 2 5 & 2 & k array |=0 k= 2 For k=2 , equation of the plane is given by | array ccc x-1 & y+1 & z 2 & 2 & 2 5 & 2 & 2 array |=0 y-z+1=0 For k=-2 , equation of the plane is given by | array ccc x-1 & y+1 & z 2 & -2 & 2 5 & 2 & -2 array |=0 y+z+1=0