- #1
Edellaine
- 11
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Homework Statement
1 a) Prove that the group (nZ, +) acts on Z by a*g = a + g for all g in nZ and for all a in Z.
b)What are the orbits?
c)How many orbits are there? Do the set of orbits remind you of anything in number theory?
Homework Equations
not sure
The Attempt at a Solution
a) For e in (nZ, +), e = 0. so a*e = a+e = a+0 = a. So the identity of (nZ, +) is also the identity on Z.
For g, h in nZ, and for a in Z, a*(g+h) = a+(g+h) = (a+g)+h = (a*g)*h.
b, c) I know what the definition of what an orbit is (here for some a in Z, O_a = {a*g = a+g | g in nZ}) I'm not sure what the question is actually asking.
For c, would the amount of orbits be equal to the amount of elements in nZ, or 2n+1?