Cho lược đồ quan hệ R = (U, F) với U= {A, B,C, D,E, G,H} và F= {AB→C, D→EG, ACD→B, C→A, BE→C, CE→AG, BC→D, CG→BD, G→ H} Tính (D)+

Which of the following is true of heuristics? a)heuristics always lead to correct solutions of a problem. b)heuristics represent commonly used approaches to the solution of a problem.c) heuristics are a slower way to solve problems than are other strategies. d)heuristics are used by computers but not by humans as problem-solving tools.