Thread: Permutations

Ok, I don't know how to go about this.

Prove that there is no permutation α such that α(12) α^-1 = (123)

Prove that there is no permutation α such that α(12) α^-1 = (124)(567)

Originally Posted by chris27

Ok, I don't know how to go about this.

Prove that there is no permutation α such that α(12) α^-1 = (123)

Prove that there is no permutation α such that α(12) α^-1 = (124)(567)

Well (1 2 3) = (1 2)(2 3), which is an even permutation.
So must be even, but this is impossible because if is an even permutation, then is odd, so is odd.
But if is odd, then is even, so is odd. So the left side is never an even permutation.

The same reasoning applies to the second problem.

Two cycles cannot be conjugate if they have different lengths for that will imply thier orders are not the same.