View Compilation Error

0_0_12701071_11510.cpp: In function `int main()':
0_0_12701071_11510.cpp:6: error: `scanf' undeclared (first use this function)
0_0_12701071_11510.cpp:6: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_12701071_11510.cpp:9: error: `getchar' undeclared (first use this function)
0_0_12701071_11510.cpp:12: error: `atan' undeclared (first use this function)
0_0_12701071_11510.cpp:15: error: `fabs' undeclared (first use this function)
0_0_12701071_11510.cpp:17: error: `printf' undeclared (first use this function)