德国老外的程序，免费开源可以计算各种不同的函数、以及四则运算，可以处理括号，还可以计算正余弦，是一款不可多得的表达式计算类和计算工具。-Foreigners in Germany program, free open-source can be calculated a variety of functions, as well as the four operations and can handle brackets, but also can calculate the positive