#include<cstdio>
#include<cstring>
#include<cmath>
#define PI acos(-1.0)
using namespace std;
double L,n,C;
double cal(double rad){
return L*rad/sin(rad);
}
int main(){
while(scanf("%lf%lf%lf",&L,&n,&C)==3&&L>=0){
double res=(1+n*C)*L;
double l=0,r=PI/2,m;
for(int i=0;i<100;i++){
m=(l+r)/2;
if(cal(m)<res)
l=m;
else
r=m;
}
printf("%.3f\n",L/(2*sin(m))*(1-cos(m)));
}
}
uva 10668 二分
最新推荐文章于 2019-07-14 00:05:43 发布