JEE Main202225 Jun 2022Evening ShiftMathematicsThree Dimensional GeometryActual
Let P be the plane passing through the intersection of the planes r → · i ^ + 3 j ^ - k ^ = 5 and r → · 2 i ^ - j ^ + k ^ = 3 , and the point 2 , 1 , - 2 . Let the position vectors of the points X and Y be i ^ - 2 j ^ + 4 k ^ and 5 i ^ - j ^ + 2 k ^ respectively. Then the points
Options
- AX and X + Y are on the same side of P
- BY and Y - X are on the opposite sides of P
- CX and Y are on the opposite sides of P
- DX + Y and X - Y are on the same side of P
Correct answer
C. X and Y are on the opposite sides of P
Step-by-step solution
We know that family of planes equation is given by, P 1 + λ P 2 = 0 ⇒ x + 3 y - z - 5 + λ 2 x - y + z - 3 = 0 2 , 1 , - 2 lies on this plane ∴ λ = 1 ⇒ So the equation of required plane is 3 x + 2 y - 8 = 0 Now let P = 3 x + 2 y - 8 = 0 So, P 1 = 3 × 1 + 2 × - 2 - 8 = - 9 P 2 = 3 × 5 + 2 - 1 - 8 = 5 Since P 1 × P 2 < 0 , So X and Y are on the opposite sides of plane P