设a，b，c均为向量，下列等式正确的是：
A.(a + b)(a-b) = a 2 - b 2 B.a.(a.b) = a 2 b C.(a.b)2 = a 2 b 2 D.(a + b) × (a - b) = a × a - b × b正确答案A
设a，b，c均为向量，下列等式正确的是：
A.(a + b)(a-b) = a 2 - b 2 B.a.(a.b) = a 2 b C.(a.b)2 = a 2 b 2 D.(a + b) × (a - b) = a × a - b × b正确答案A
