Question

What is the angle between `<-3 , 5 ,2 >` and `< -2, 7 ,-2 >`?

Answer 1

The required angle is `37.34^0`

Explanation:

Let `vecu =<-3,5, 2> and vecv =<-2,7,-2> ; theta` be the angle between them ; then we know `cos theta= (vecu*vecv)/(||vecu||*||vecv||)=((-3.-2)+(5*7)+(2* -2))/(sqrt((-3)^2+5^2+2^2)* sqrt((-2)^2+7^2+(-2)^2)` `= 37/(sqrt38*sqrt57)==0.795:. theta=cos^-1(0.795)=37.34^0`[Ans]