The International Union of Pure and Applied Chemistry (IUPAC) is an international non-governmental organization devoted to the advancement of chemistry. It has as its members national chemistry societies. It is the recognized authority in developing standards for the naming of chemical compounds, through its Interdivisional Committee on Nomenclature and Symbols. It is a member of the International Council for Science (ICSU).
... we can conveniently complete the square[?]. To "complete the square" is to add a constant (i.e., in this case, a quantity that does not depend on x) to the expression to ...