KCET2022MathematicsThree Dimensional Geometry
The distance of the point whose position vector is (2 i + j - k ) from the plane r ( i -2 j +4 k )=4 is
Options
- A8 21
- B8 21
- C- 8 21
- D- 8 21
Correct answer
A. 8 21
Step-by-step solution
Equation of plane r ( i -2 j +4 k )=4 aligned & r n =d & Point a =2 i + j - k & n = i -2 j +4 k , d=4 & Distance = | a n -d| | n | = | (2 i + j - k ) ( i -2 j +4 k )-4 1^2+(-2)^2+4^2 | & = | 2-2-4-4 1+4+16 |= | -8 21 |= 8 21 & aligned