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Groups and FieldsMediumHomomorphisms and Isomorphisms

Homomorphisms and Isomorphisms · Medium problem

The map φ:Z6→Z6\varphi:\mathbb Z_6\to\mathbb Z_6, φ(x)=5x mod 6\varphi(x)=5x\bmod6, is an isomorphism. Find φ−1(2)\varphi^{-1}(2).