z·z=|z|~2(见高级中学课本《代数》甲种本第二册206页)是一个非常重要的公式,它外形很优美、对称、结构简单,它说明了复数z与z及其模的平方间的关系。本文就是根据这些特点,阐明它在求值、最值、不等式的证明、正三角形等问题,特别是涉及复数的恒等式的证明诸方面的应用。 z·z=|z|~2 (See “Algebra, Algebra, Volume 2, Page 206,” in the High School Textbook) is a very important formula. It has a beautiful, symmetrical, and simple structure. It illustrates the plural z and z. The relationship between the square of its model. This article is based on these characteristics, to clarify its value in the evaluation, the most value, inequality, the positive triangle and other issues, especially the application of plural aspects of the identification of identity.