- #1
zardiac
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Abstract Algebra, order of ab is equal to the order of a times the order of b??
Hi!
I am working on some problems in abstract algebra and I am stuck at the moment. I hope some of you guys could help me out a little.
a and b are two elements in a group G.
Assume that ab=ba.
Show that if GCD(o(a),(ob))=1, then o(ab) = o(a)*o(b)
Where o(a) is the order of a. (i.e. a^(o(a))=1.)
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I call o(a)=n, o(b)=m, o(ab)=k, then show that k=mn.
Since SGD(m,n)=1, then m and n are coprime integers, and I have this relation: 1=sn+tm, where s and t are some integers.
However I am stuck now and I am not sure how to use this or where to start.
So any suggestions would be very appreciated.
Thanks in advance
Hi!
I am working on some problems in abstract algebra and I am stuck at the moment. I hope some of you guys could help me out a little.
Homework Statement
a and b are two elements in a group G.
Assume that ab=ba.
Show that if GCD(o(a),(ob))=1, then o(ab) = o(a)*o(b)
Where o(a) is the order of a. (i.e. a^(o(a))=1.)
Homework Equations
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The Attempt at a Solution
I call o(a)=n, o(b)=m, o(ab)=k, then show that k=mn.
Since SGD(m,n)=1, then m and n are coprime integers, and I have this relation: 1=sn+tm, where s and t are some integers.
However I am stuck now and I am not sure how to use this or where to start.
So any suggestions would be very appreciated.
Thanks in advance