The purpose of this study is to clarify the practice of computer use in education and teachers' perceptions of computer education. It also sheds light on the relationship between computers and mathematics by means of a survey sent to schools in the state of Oregon. The survey provides data to view (1) profiles of respondents, (2) the practical use of calculators, (3) the practical use of computers (hardware, software, computer use in each subject, perception about future use and so on), and (4) perceptions about computer and mathematics education.
J. Metz constructed geometrically the coefficient b of linear term from the given graph of quadratic function y=ax• +bx+c as a vertical vector. In this paper,we consider two geometric constructions which expressing explicitly the coefficient b, and constructions of a.