View Compilation Error

0_0_28370943_8989.cpp: In function 'int main()':
0_0_28370943_8989.cpp:13:29: error: 'M_E' was not declared in this scope
             ans = d*log10(d/M_E) + log10(2*M_PI*d)/2 + 1;
                             ^
0_0_28370943_8989.cpp:13:44: error: 'M_PI' was not declared in this scope
             ans = d*log10(d/M_E) + log10(2*M_PI*d)/2 + 1;
                                            ^