Exercise
The (multiplicative) inverse on Z/11Z is
a unary operation.
a binary operation.
neither a binary nor a unary operation.
Close. The element 0 has no inverse, so the operation is not defined
on all of Z/11Z.
Nevertheless, one might speak of a unary operation on the set of nonzero elements of Z/11Z, or extend the inverse to a unary operation by prescribing the image of 0 to be, say, 0.
Nevertheless, one might speak of a unary operation on the set of nonzero elements of Z/11Z, or extend the inverse to a unary operation by prescribing the image of 0 to be, say, 0.
No way, there is just one argument, so it is much closer to being a unary operation.
True.