If A=<2,5,3> and B=<7,4,9>, what is AB||A||||B||?

1 Answer
Apr 8, 2016

AB||A||||B||=107,48

Explanation:

A=<2,5,3>
B=<7,4,9>

let's find ||A||

||A||=A2x+A2y+A2z
||A||=(2)2+(5)2+32
||A||=4+25+9
||A||=38

let's find ||B||

||B||=B2x+B2y+B2z
||B||=(7)2+42+(9)2
||B||=49+16+81
||B||=146

let's find AB

AB=AxBx+AyBy+AzBz

AB=142027
AB=33

AB||A||||B||=33(38146)

AB||A||||B||=335548
AB||A||||B||=3374,48
AB||A||||B||=107,48