已知△ABC的顶点分别是A(1,2,3),B(3,7,5)C(2,4,7),求|AB→×AC→|

2025-06-26 23:43:58
推荐回答(1个)
回答1:

A(1,2,3),B(3,7,5)C(2,4,7),
向量AB=(2,5,2),AC=(1,2,4),
AB×AC=
i j k

2 5 2
1 2 4
=(16,-6,-1),
它的模=√273.