设a=3i-j-2k,b=i+j-2k,c=3a+ - 知识问答

设a=3i-j-2k,b=i+j-2k,c=3a+2b,c在三个坐标轴上的投影和分向量

1个回答

c=3a+2b
=3(2,-1,-2)+2(1,1,-2)
=(6+2,-3+2,-6-4)
=(8,-1,-10)
=8i-j-10k
投影为8 -1 -10
分向量为8i -j -10k
你说对不对?

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