c语言中怎么编写倒三角函数

包含头文件 math.h

反3角函数有 acos(double),asin(double),atan(double),atan(double,double),

返回值 double 型，弧度值。转角度要 *180.0/3.1416

例如：

#include 

#include

#include

int main()

{

double x=0.5;

printf("acos=%.2lf degrees\n",acos(x) * 180.0/3.1416); 

printf("asin=%.2lf degrees\n",asin(x) * 180.0/3.1416); 

printf("atan=%.2lf degrees\n",atan(x) * 180.0/3.1416); 

printf("atan2=%.2lf degrees\n",atan2(1.0,2.0) * 180.0/3.1416); 

return 0;

}