JEE MainMathematicsThree Dimensional Geometry
If the length of the perpendicular drawn from the point P( , 3, 5) , where > 2 , on the line x-1 1 = y-2 1 = z-3 1 is 2 units, and is the plane containing the point P and the given line, then the square of the perpendicular distance of the point A(5, 4, 3) from the plane is equal to
Options
- A6
- B0
- C14
- D4
Correct answer
A. 6
Step-by-step solution
Let a point on the line x-1 1 = y-2 1 = z-3 1 = be M( +1, +2, +3) . The direction ratios of the line are 1, 1, 1 . The direction ratios of the line segment joining P( , 3, 5) and M are +1- , -1, -2 . Since PM is perpendicular to the given line: 1( +1- ) + 1( -1) + 1( -2) = 0 3 - - 2 = 0 = +2 3 The square of the distance PM is 2 : ( +1- )^2 + ( -1)^2 + ( -2)^2 = 2 Substituting = +2 3 : ( 5-2 3 )^2 + ( -1 3 )^2 + ( -4 3 )^2 = 2 (25 - 20 + 4 ^2) + ( ^2 - 2 + 1) + ( ^2 - 8 + 16) = 18 6 ^2 - 30 + 42 = 18 6 ^2 - 30 + 24