View Compilation Error

0_0_37894318_10056.cpp:13:28: error: 'acos' was not declared in this scope
 const double pi = acos(-1.0);
                            ^
0_0_37894318_10056.cpp:19:30: error: 'sqrt' was not declared in this scope
 const double gold = (sqrt(5.0) - 1) / 2;
                              ^