- #1
dorin1993
- 11
- 0
Hi guys,
I have quastion about groups:
G is abelian group with an identity element "e".
If xx=e then x=e.
Is it true or false?
I was thinking and my feeling is that it's true but I just can't prove it.
I started with:
(*) ae=ea=a
(*) aa^-1 = a^-1 a = e
those from the definition of Group
and now the assuming: aa=e
then:
aa^-1 = e = aa
a=a^-1
==> a^-1 a = aa = e
that's all i got.
Is anyone can halp?
thank you!
I have quastion about groups:
G is abelian group with an identity element "e".
If xx=e then x=e.
Is it true or false?
I was thinking and my feeling is that it's true but I just can't prove it.
I started with:
(*) ae=ea=a
(*) aa^-1 = a^-1 a = e
those from the definition of Group
and now the assuming: aa=e
then:
aa^-1 = e = aa
a=a^-1
==> a^-1 a = aa = e
that's all i got.
Is anyone can halp?
thank you!