Two vectors u and v are given $u=5i-9j-9k, v=4/5i+4/3j-k$ , how do you find their dot product?

Question

4584 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-12-11T06:28:31

The answer is $=1$

If we have 2 vectors $vecA=〈a,b,c〉$

and $vecB=〈d,e,f〉$

$vecA.vecB=〈a,b,c〉.〈d,e,f〉=ad+be+cf$

Here. $vecu=〈5,-9,-9〉$ and

$vecv=〈4/5,4/3,-1〉$

The dot product is

$=5*4/5-9*4/3+(-9*-1)$

$=4-12+9=1$

Two vectors u and v are given u=5i-9j-9k, v=4/5i+4/3j-ku=5i-9j-9k, v=4/5i+4/3j-k, how do you find their dot product?