View Compilation Error

0_0_33975706_18127.cpp: In function 'int isPrime(int)':
0_0_33975706_18127.cpp:12:34: error: 'sqrt' was not declared in this scope
     n_sqrt = floor(sqrt((float) n));
                                  ^
0_0_33975706_18127.cpp:12:35: error: 'floor' was not declared in this scope
     n_sqrt = floor(sqrt((float) n));
                                   ^