问题 填空题
已知空间三个向量
a
=(1,-2,-17),
b
=(x,2,-4),
c
=(-1,y,3),若它们分别两两垂直,则x=______,y=______.
答案

a
=(1,-2,-17),
b
=(x,2,-4),
c
=(-1,y,3)分别两两垂直,

x-4+68=0
-1-2y-51=0
-x+2y-12=0

解得x=-64,y=-26.

故答案为:-64,-26.

单项选择题
单项选择题