The distance of the point from the plane measured along the line is
- A.
- B.
- C.
- D.
Show answer and solution
Correct option: B
Solution
The line through (1, -5, 9) parallel to x = y = z has direction (1,1,1), parametrized as (1+t, -5+t, 9+t). Substituting into the plane x - y + z = 5: (1+t) - (-5+t) + (9+t) = 5 → 15 + t = 5 → t = -10. The point of intersection is (1-10, -5-10, 9-10) = (-9, -15, -1). Distance = √((1-(-9))² + (-5-(-15))² + (9-(-1))²) = √(100+100+100) = 10√3.
[JEE Main 2016]