JEE Main201912 Apr 2019Evening ShiftMathematicsThree Dimensional GeometryActual
The length of the perpendicular drawn from the point ( 2 , 1 , 4 ) to the plane containing the lines r → = i ^ + j ^ + λ i ^ + 2 j ^ - k ^ and r → = ( i ^ + j ^ ) + μ ( - i ^ + j ^ - 2 k ^ ) is
Options
- A1 3
- B3
- C3
- D1 3
Correct answer
C. 3
Step-by-step solution
n → = i j k 1 2 - 1 - 1 1 - 2 = - 3 i ^ + 3 j ^ + 3 k ^ Equation of plane - 3 x - 1 + 3 y - 1 + 3 z = 0 ⇒ x - y - z = 0 d ( 2,1 , 4 ) = | 2 - 1 - 4 | 1 2 + 1 2 + 1 2 = 3