00:01
A relation is given as a square minus b square is divisible by 4.
00:16
So we have to show that this relation is equivalence.
00:20
So for showing equivalence we must show their three properties.
00:24
The first is reflexive, then symmetric and then transitive.
00:29
Reflexive means if these and this, this element should belongs to this relation.
00:35
B is also a, then this will be a square minus a square that is equals to 0.
00:42
0 is divisible by any number.
00:44
Therefore this relation is reflexive.
00:48
It is reflexive.
00:52
Now for the symmetric, if a and b belongs to the relation that mean a square minus b square.
01:01
4 divides this term.
01:03
We can take negative common, it will be negative time b square minus a square.
01:09
From this we can say that 4 is also divisible by b square minus a square...