conjf, conj, conjl

#include <stdio.h>
#include <complex.h>
 
int main(void)
{
 double complex z = 1.0 + 2.0*I;
 double complex z2 = conj(z);
 printf ("The conjugate of %.1f%+.1fi is %.1f%+.1fi\n",
 creal (z), cimag (z), creal (z2), cimag (z2));
 
 printf ("Their product is %.1f%+.1fi\n", creal (z*z2), cimag (z*z2));
}

The conjugate of 1.0+2.0i is 1.0-2.0i
Their product is 5.0+0.0i