回答: #A X B = -2i-13j + 8k# 説明: #A = 4i + 0j + 1k# #B = -1i + 2j + 3k# #A X B = i(A_j B_k-A_k B_j)-j(A_i B_k-A_k B_i)+ k(A_i B_j-A_J B_i)# #A X B = i(0 * 3-1 * 2)-j(4 * 3 + 1 * 1)+ k(4 * 2 + 0 * 1)# #A X B = i(-2)-j(13)+ k(8)# #A X B = -2i-13j + 8k#