0_0_18333795_29295.cpp:2:2: error: invalid preprocessing directive #inxclude #inxclude<math.h> ^ 0_0_18333795_29295.cpp: In function 'int main()': 0_0_18333795_29295.cpp:8:9: error: 'fabs' was not declared in this scope a=fabs(a); ^