00:01
In this question we have been given that g be an abelian group and operation of multiplication is defined by ab equal to 0 for all ab belongs to g.
00:09
Then we have to show that g is a ring.
00:12
So since it is abelian, so let us see the first part.
00:16
So g is abelian with respect to addiction it is given.
00:28
And now we see whether it is closed or not.
00:31
Okay, so let a and b belongs to g, correct? then ab will be equal to zero which clearly belongs to g.
00:44
So this implies that ab belongs to g.
00:47
Okay, so we can say that it is closed under multiplication.
00:52
Okay, so hence closure property is satisfied.
00:55
Now we will see the associativity with respect to multiplication.
01:00
Okay.
01:00
Okay, so k times bc will be equal to a time zero which is same as zero, correct.
01:10
And if we consider ab times c, so it will be zero times c, which is again zero.
01:17
So this implies that ab c is equal to kb times of c.
01:23
So this is for the associativity that is getting done here...