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QUESTION

Evaluate \textbf{a.b} where
$\textbf{a}=2\textbf{i}-\textbf{j}+2\textbf{k}$ and
$\textbf{b}=\textbf{i}+\textbf{k}$.

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ANSWER

$\textbf{a.b}=(2,-1,2).(1,0,1)=2+0+2=4$




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