The question is as attached in the picture.
The Attempt at a Solution
I understand and got the answer to part (a) but from (b) onwards I am completely lost. Here are my assumptions:
1)Edges of 'cube' are still of length a
2)Successive planes are parallel
But, there is some things remain unknown:
1)Where is the origin at? The centre of the cube? or at the bottom leftmost point?
2)Why does the plane pass through (a/2, 0, a/2)?
3) Do we assume that the plane contains the origin? Then won't the equation be
r . n = 0?