#include<stdio.h>
#include<stdlib.h>
#include<math.h>

typedef struct double_matrix{
  int r,c;
  double **data;
}doubleMatrix;

void* newDoubleMatrix(doubleMatrix *a,int r,int c,void *WorkMemory){
  int i;
  a->r=r; a->c=c;
  a->data = (double**)WorkMemory; WorkMemory = (void*)(a->data + r);
  for(i=0;i<r;i++){
    a->data[i] = (double*)WorkMemory;
    WorkMemory = (void*) (a->data[i] + c);
  }
  return WorkMemory;
}

void doubleMatrixSetZero(doubleMatrix *a){
  int i,j;
  for(i=0; i<(a->r); i++) for(j=0; j<(a->c); j++) a->data[i][j]=0;
}

void doubleMatrixSetIdentity(doubleMatrix *a){
  int i,mx;
  mx=a->r; if(mx>a->c) mx=a->c;
  doubleMatrixSetZero(a);
  for(i=0;i<mx;i++) a->data[i][i] = 1;
}

void doubleMatrixMultiple(doubleMatrix *a,doubleMatrix *b,doubleMatrix *res){
  int i,j,k;
  doubleMatrixSetZero(res);
  for(i=0;i<(res->r);i++){
    for(k=0;k<(b->r);k++) if(a->data[i][k]!=0.0){
      for(j=0;j<(res->c);j++) res->data[i][j] += a->data[i][k] * b->data[k][j];
    }
  }
}

void doubleMatrixPower(doubleMatrix *a,doubleMatrix *res,int k,void *WorkMemory){
  int i,j,n=a->r;
  doubleMatrix tmp1,tmp2;
  
  res->r=res->c=n;
  if(k==0){ doubleMatrixSetIdentity(res); return; }
  if(k==1){ for(i=0;i<n;i++) for(j=0;j<n;j++) res->data[i][j]=a->data[i][j]; return; }
  if(k==2){ doubleMatrixMultiple(a,a,res); return; }

  WorkMemory = newDoubleMatrix(&tmp1,n,n,WorkMemory);
  doubleMatrixPower(a, &tmp1, k/2, WorkMemory);
  if(k%2==0) doubleMatrixMultiple(&tmp1,&tmp1,res);
  else {
    WorkMemory = newDoubleMatrix(&tmp2,n,n,WorkMemory);
    doubleMatrixMultiple(&tmp1,&tmp1,&tmp2);
    doubleMatrixMultiple(a,&tmp2,res);
  }
}

int main(){
  int T;
  void *mem = malloc(10000000);
  
  scanf("%d",&T);
  while(T--){
    int M, N; double X, cosX, sinX;
    int i;
    doubleMatrix mt, pw;
    double res;
    void *mem_next;

    scanf("%d%d%lf",&M,&N,&X);

    cosX = cos(X);
    sinX = sin(X);
    mem_next = newDoubleMatrix(&mt,2*M,2*M,mem); /* create a matrix */
    mem_next = newDoubleMatrix(&pw,2*M,2*M,mem_next);
    N--;

    doubleMatrixSetZero(&mt);
    for(i=0;i<M;i++) mt.data[i][i+M] += 1;
    for(i=0;i<M;i++){
      if(i) mt.data[i+M][i-1+M] += sinX;
      mt.data[i+M][i+M] += 2*cosX;
      mt.data[i+M][i] -= 1;
    }

    doubleMatrixPower(&mt,&pw,N,mem_next); /* calculate pw = mt^N */
    res = sinX * pw.data[2*M-1][M];

    printf("%.3f\n",res); /* %.10f is also accepted */
  }
  return 0;
}