View Compilation Error

0_0_18030759_4698.cpp:52:9: error: stray '\' in program
         printf("Case #%d: %.6lf\n",ta++,ans\n);
         ^
0_0_18030759_4698.cpp: In function 'int main()':
0_0_18030759_4698.cpp:52:45: error: expected ')' before 'n'
         printf("Case #%d: %.6lf\n",ta++,ans\n);
                                             ^