NTA Abhyas JEE Main2020MathematicsThree Dimensional GeometryPractice
The distance of the plane x + 2 y - z = 2 from the point 2 , - 1 , 3 , measured in the direction with the direction ratios 2,2 , 1 is
Options
- A1 units
- B2 units
- C3 units
- D4 units
Correct answer
C. 3 units
Step-by-step solution
Direction ratios given are 2 , 2 , 1 The line is x - 2 2 = y + 1 2 = z - 3 1 = r Any general point on this line is 2 r + 2,2 r - 1 , r + 3 If it lies on the plane x + 2 y - z = 2 , then 2 r + 2 + 2 2 r - 1 - r + 3 = 2 ⇒ 2 r + 4 r - r + 2 - 2 - 3 = 2 ⇒ 5 r = 5 ⇒ r = 1 The point on the plane is 4,1 , 4 and its distance from 2 , - 1,3 is 4 - 2 2 + 1 + 1 2 + 4 - 3 2 = 4 + 4 + 1 = 3