- #1
Murtuza Tipu
- 49
- 2
Homework Statement
Let S be the subset of group G that contains identity element 1 such that left co sets aS with a in G, partition G .Probe that S is a subgroup of G.
Homework Equations
{hS : h belongs to G } is a partition of G.
The Attempt at a Solution
For h in S if I show that hS is S then that would imply that S is closed.
Now hS is a partition of S and contains h since 1 is in S and h is in S also.Hence h belongs to S intersection hS.
More over both these partition or two partition are disjoint or equal sets.
Hence h=hS which says that S is closed.