he elements of the Klein <span>44</span>-group sitting inside <span><span>A4</span><span>A4</span></span> are precisely the identity, and all elements of <span><span>A4</span><span>A4</span></span>of the form <span><span>(ij)(kℓ)</span><span>(ij)(kℓ)</span></span> (the product of two disjoint transpositions).
Since conjugation in <span><span>Sn</span><span>Sn</span></span> (and therefore in <span><span>An</span><span>An</span></span>) does not change the cycle structure, it follows that this subgroup is a union of conjugacy classes, and therefore is normal.
The rules of significant figures are: 1. all non zeros are significant. 2. trailing zeros are significant. 3. zeros between non-zeros are signifincant. Hence, applying these to the given. A. 4 sig figs B. 1 sig fig C.6 sig figs D.1 sig fig
