设点O(0,0,0),A(1,-2,3),B(-1,2,3),C(1,2,-3),则OA•BC=______.-数学

题目简介

设点O(0,0,0),A(1,-2,3),B(-1,2,3),C(1,2,-3),则OA•BC=______.-数学

题目详情

设点O(0,0,0),A(1,-2,3),B(-1,2,3),C(1,2,-3),则
OA
BC
=______.
题型:填空题难度:偏易来源:不详

答案

因为点O(0,0,0),A(1,-2,3),B(-1,2,3),C(1,2,-3),
所以
OA
=(1,-2,3),
BC
=(2,0,-6)

OA
BC
=(1,-2,3)•(2,0,-6)=2-18=-16.
故答案为:-16.

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