为Foxbase+建立三角函数

Building the Triangle Function for Foxbase

利用数学中的泰勒级数、数值积分等知识和Foxbase+提供的自定义函数功能，设计出了计算三角函数和反三角函数的自定义函数程序，解决了Focbase+中三角函数的计算问题。

Based on the knowledge of Tailor series in maths and the numerical value integration and the knowledge of user defined function (UDF) in Foxbase+, this al'ticle offers a program of UDF to calculate the triangle function and reverse triangle function, thus solving the calculating problems of triangle function in Foxbase +.