使用指南SQL 手册SQL 函数数学函数tan本页总览tantan description Syntax DOUBLE tan(DOUBLE x) 返回x的正切值,x为弧度值. example mysql> select tan(0);+----------+| tan(0.0) |+----------+| 0 |+----------+mysql> select tan(1);+--------------------+| tan(1.0) |+--------------------+| 1.5574077246549023 |+--------------------+ keywords TAN