Question

Distance between parallel planes $2x - 2y + z + 3 = 0$and $4x - 4y + 2z + 5 = 0$ is

• A. $\frac{2}{3}$
• B. $\frac{1}{3}$
• C. $\frac{1}{6}$
• D. 2

Answer 1

Answer: (C)

$\frac{1}{6}$

Answer 2

The required distance is given by

$\left| \frac { 3 } { \sqrt { 2 ^ { 2 } + 2 ^ { 2 } + 1 ^ { 2 } } } - \frac { 5 } { \sqrt { 4 ^ { 2 } + 4 ^ { 2 } + 2 ^ { 2 } } } \right| = \left| 1 - \frac { 5 } { 6 } \right| = \frac { 1 } { 6 }$.