Please solve RD Sharma Class 12 Chapter 26 Directions Cosines and Direction Ratio Exercise Multiple Choice Question, question 4 Maths textbook solution.
Answer: (a) 7
Hint: Distance between planes passing through points is the length of edge
Given: Points (2,3,5) and (5,9,7)
Solution: In geometry parallelopiped is a three dimension figure with six parallelogram
z
Let P and Q be the points. So, all the plane passes through these points. Now distance between planes joining (a,0,0) and (b,0,0) is |b-a|. Similarly, we can generate 3 pairs of plane from each coordinate from these 2 points.
For x-coordinate, value of a is
a=|2-5|=3
For y-coordinate, value of b is
b=|3-9|=6
For z-coordinate value of c is
c=|5-7|=2
The edges of parallelopiped are 3,6,2
Length of diagonal=
Therefore, the length of diagonal is 7. Hence option (a) 7 is correct.