3 若 A 為一向量，f 為一純量，則下列敘述何者錯誤？
(A)∇ ⋅(∇ × A) = 0
(B)∇ × (∇f ) = 0
(C) ∇ ⋅( fA) = f (∇ ⋅ A) + A ⋅∇f
(D)∇× ( fA) = A ×∇f + f ∇× A

答案：登入後查看
統計： A(1), B(0), C(2), D(3), E(0) #860962