JEE MainMathematicsThree Dimensional Geometry
If ( ^2 + - 4, 2 ^2 - 8, 3 ) is the image of the point ( , 0, 0) in the plane x + 2y + z = 40 , then the possible value(s) of is (are)
Options
- AOnly 4 and -1
- BOnly 4
- COnly 4 and -5
- DOnly 4 , -1 and -5
Correct answer
B. Only 4
Step-by-step solution
Let the given point be P( , 0, 0) and its image be P'( ^2 + - 4, 2 ^2 - 8, 3 ) . For P' to be the image of P in the plane x + 2y + z = 40 , two conditions must be satisfied: 1. The vector PP' must be parallel to the normal vector of the plane. 2. The midpoint of P and P' must lie on the plane. The normal vector to the plane is n = (1, 2, 1) . The vector PP' is ( ^2 - 4, 2 ^2 - 8, 3 ) . Applying the parallelism condition, the components must be proportional: ^2 - 4 1 = 2 ^2 - 8 2 = 3 1 The first two parts are identi