以往在代数学教科书里虚数是作为代数方程的虚根来教的,由于接触不到它的真正面目,所以学生往往体会不到复数的实用价值,但是一旦接触到复数的极坐标形式或欧拉公式的简洁而出色的应用后,就有可能对复数的概念进一步的了解。在这篇短文中作者准备叙述复数在几何学中的一个应用,内容仅限于在坐标变换和一般二次曲线论的应用方面。 (一) 坐标变换 In the past, the imaginary numbers in algebra textbooks were taught as the imaginary roots of algebraic equations. Because they did not reach the true face of the algebraic equations, students often did not realize the practical value of complex numbers, but once they came into contact with complex polar coordinates or Euler’s formulas. After a simple and excellent application, it is possible to further understand the concept of plural. In this short article, the author is going to describe an application of complex numbers in geometry, which is limited to the application of coordinate transformation and general quadratic curve theory. (a) coordinate transformation