View Compilation Error

0_0_31977590_9208.cpp: In function 'double answer(int, int)':
0_0_31977590_9208.cpp:6:19: error: 'srt' was not declared in this scope
     double t=srt(2);
                   ^
0_0_31977590_9208.cpp: In function 'int main()':
0_0_31977590_9208.cpp:24:42: error: 'answr' was not declared in this scope
         printf("%.3lf\n",fabs(answr(x1,y1)-answer(x2,y2)));
                                          ^