AP EAMCET202315 May 2023Morning ShiftMathematicsThree Dimensional GeometryActual
The distance between two parallel planes a x+b y+c z+d₁=0 , a x+b y+c z+d₂=0 is given by |d₁-d₂ | a^2+b^2+c^2 . If the plane 2 x-y+2 z+3=0 has the distances 1 3 and 2 3 units from the planes 4 x-2 y+4 z+ =0 and 2 x-y+2 z+ =0 respectively, then the maximum value of + is
Options
- A15
- B5
- C13
- D9
Correct answer
C. 13
Step-by-step solution
Given equation are 2 x-y+2 z+3=0...(1) and 4 x-2 y+4 z+ =0 2 x-y+2 z+ 2 =0...(2) and 2 x-y+2 z+ =0...(3) Since distance between equation (1) and (2) is 1 3 . Hence, | 2 -3 | 4+1+4 = 1 3 =8 Since distance between equation (1) and (3) is 2 3 . Hence, | -3| 4+1+4 = 2 3 =5 Therefore + =8+5=13