/in/foo.c: In function 'main':
/in/foo.c:10:11: warning: implicit declaration of function 'pow' [-Wimplicit-function-declaration]
   y = 2 * pow(x, 2) + 4 * x - 5;
           ^~~
/in/foo.c:10:11: warning: incompatible implicit declaration of built-in function 'pow'
/in/foo.c:10:11: note: include '<math.h>' or provide a declaration of 'pow'
/in/foo.c:12:7: warning: incompatible implicit declaration of built-in function 'pow'
   y = pow((5 * x + 10), 0.5);
       ^~~
/in/foo.c:12:7: note: include '<math.h>' or provide a declaration of 'pow'