demo_headfile.cpp

对于一个初涉VC＋＋的人来书

#include<iostream.h>
#include<math.h>

const double pi(3.14159265);

void main()
{
    double a,b;

    cin>>a;
    b=a*pi/180;

    cout<<"sin("<<a<<")="<<sin(b)<<endl;
    cout<<"cos("<<a<<")="<<cos(b)<<endl;
    cout<<"tan("<<a<<")="<<tan(b)<<endl;
}