Question

An element x of set S is "idempotent for" the operation * if x*x=x. How do I find the idempotent elements of ? (Z is the set of all integers)

Answer 1

do you have a definition for idempotent, or is that the definition?

Answer 2

They want you to find which integers will satisfy this equation x+x = x

The operation is + so that's why * gets replaced with +

Answer 3

Oh ok, so it'd be 0 in this case

Answer 4

correct