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。-Germany foreigners procedures to free and open source can calculate a variety of functions, as well as four operations that can handle brackets, you can also calculate the sine and c