Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

When solving an equation, can I use the notation $x \in \{a, b, c\}$ to mean that $x=a$, $x=b$ and $x=c$ are all possible solutions to the equation?

share|cite|improve this question
Well, $x \in \{a,b,c\}$ means that $x=a, x=b$ or $x=c$ but does not mention the word "solution" anywhere. – GEdgar Oct 2 '11 at 13:40
up vote 12 down vote accepted

It is indeed an acceptable notation.

Example: $x^3-x=0$ exactly for $x\in\{0,1,-1\}$.

share|cite|improve this answer

By saying that $x \in \{a,b,c\}$, by definition of element of set you are saying that $x=a, x=b, x=c$ . Read more about element of set here:

share|cite|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.