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)∇×

問題詳情

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：D
難度：困難0.2
統計：A(1),B(0),C(2),D(1),E(0)