If $A= <-3 ,8 ,-1 >$ and $B= <0 ,7 ,2 >$ , what is $A*B -||A|| ||B||$ ?

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Answer 1 · 2017-02-08T07:24:46

The answer is $=-8.63$

The dot product is

$vecA.vecB=<-3,8,-1>.<0,7,2>=0+56-2=54$

The modulus of $vecA$ is

$||vecA||=||<-3,8,-1>=sqrt(9+64+1)=sqrt74$

The modulus of $vecB$ is

$||vecB||=||<0,7,2>=sqrt(0+49+4)=sqrt53$

Therefore,

$vecA.vecB-||vecA||*||vecB||$

$=54-sqrt74*sqrt53$

$=54-62.63$

$=-8.63$

If A= <-3 ,8 ,-1 >A= <-3 ,8 ,-1 > and B= <0 ,7 ,2 >B= <0 ,7 ,2 >, what is A*B -||A|| ||B||A*B -||A|| ||B||?