[1,4,-2]和[3,-6,4]的叉积是多少?

[1,4,-2]和[3,-6,4]的叉积是多少?
Anonim

回答:

#A X B = 4i-10j-18k#

说明:

#A = I + 4J-2K#

#B = 3I-6J + 4K#

#AXB = 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))#

#AXB = I(4 * 4 - (( - 2)*( - 6))) - J(1 * 4-(3 *( - 2))+ K(1 *( - 6) - (3 * 4 ))#

#A X B = i(16-12)-j(4 + 6)+ k(-6-12)#

#A X B = i(4)-j(10)+ k(-18)#

#A X B = 4i-10j-18k#