Question

Find the angle 0 between the vectors. u=(1, 1, 1, 0), v = (4, 4, 4, 4).

Answer 1

30 degrees

Explanation:

u dot v=1*4+1*4+1*4+0*4=4+4+4+0=12

|u|=sqrt(1^2+1^2+1^2+0^2)=sqrt(3)

|v|=sqrt(4^2+4^2+4^2+4^2)=sqrt(4*4^2)=2*4=8

cos(theta)=u dot v/(|u||v|)

cos(theta)=12/(sqrt(3)*8)

cos(theta)=3/(sqrt(3)*2)

cos(theta)=sqrt(3)/2

theta=30 degrees