抄録
This paper discusses the usages of variables in mathematics, especially those of variables in polynomials and propositional variables. As the conclusion, variables in polynomials and propositional variables take a role of transcendental elements and that of generators. In this sense, the point in common between these variables and letters in identities is that we can substitute such letters with any elements. In addition, this paper shows the usages of unknowns in equations,coordinate variables and probabilistic variables with the references of past literatures, and discusses the usages of dependent variables and independent variables as a future work.
