渐开线函数工具

#include 
#include 
#include 
#include 
#include  
#define PI 3.1415926
using namespace std;
double  inv(double a)
{	
	return tan(a)-a;
}
int main()
{

	int i;
	while(1)
	{
	std::cout<<"****************************"<>i;
	system("cls");
	switch(i)
	{
		case 0:return 0;
		case 1:
			{
				double a;
				std::cout<<"请输入十进制压力角:";
				std::cin>>a;
				std::cout<<"渐开线函数值："<>sum;
				a=0;b=atan(1.0)*2;
				while(b-a>1e-12)
					{   
						c=(a+b)/2;
						inv(c)>sum?b=c:a=c;
					}	
				std::cout<<"反渐开线函数值为："<<(a+b)/2/atan(1.0)*45<<"度"<>a;
				std::cout<<"请输入螺旋角的值：";
				std::cin>>b;
				std::cout<<"渐开线函数的比值"<< fixed << setprecision(6) <