UPSC NDA Math Model Paper 2

We have to find the distance of the point (2, 3, -5) from the plane x + 2y - 2z - 9 = 0
As we know that, the distance between the point and the plane is given by |

Ax1+By1+Cz1−d

√A2+B2+C2

|
Here, x1=2,y1=3 and z1=−5
So, the distance of the given point form the given plane = |

2×1+2×3+2×5−9

√12+(−2)2+(2)2

|
=|

9

√9

|
So, the distance between the plane and the point is 3 units
Hence, option D is the correct answer.