Inline If Statement In PHP

I'm trying to working with inline if-statement but it's not working properly here is my code:

$subject_set = ($public) ? 'find_all_subjects()' : 'find_all_subjects(FALSE)';

Please tell me which thing i'm doing wrong in it and this is my normal statement:

if($public){$subject_set = find_all_subjects();}else{$subject_set = find_all_subjects(FALSE);}