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QUESTION

If  ${\bf a}={\bf i}+{\bf j}+{\bf k}$   and ${\bf b}={\bf i}-2{\bf
j}-{\bf k}$ find ${\bf a}\times{\bf b}$.

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ANSWER

${\bf a}=(1,1,1),\ {\bf b}=(1,-2,-1)$

$\textbf{a}\times\textbf{b}=(-1-(-2),1-(-1),-2-1)={\bf i}+2{\bf
j}-3{\bf k}$




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