What is the angle between <-4,0,1 > and <-6,-1,0> ?

1 Answer
Jul 6, 2017

The angle is =16.9º

Explanation:

The angle between vecA and vecB is given by the dot product definition.

vecA.vecB=∥vecA∥*∥vecB∥costheta

Where theta is the angle between vecA and vecB

The dot product is

vecA.vecB=〈-4,0,1〉.〈-6,-1,0〉=24+0+0=24

The modulus of vecA= ∥〈-4,0,1〉∥=sqrt(16+0+1)=sqrt17

The modulus of vecB= ∥〈-6,-1,0〉∥=sqrt(36+1)=sqrt37

So,

costheta=(vecA.vecB)/(∥vecA∥*∥vecB∥)=24/(sqrt17*sqrt37)=0.96

theta=16.9º