What is the dot product of $<5,4,-4>$ and $<-4,1,5 >$ ?

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Answer 1 · 2016-03-03T19:38:49

$a*b=4$

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$a=<5,4,-4>" "b=<-4,1,5>$
$a*b=5*(-4)+4*1+(-4)*5$
$a*b=-20+4-20$
$a*b=4$

What is the dot product of <5,4,-4><5,4,-4> and <-4,1,5 ><-4,1,5 >?