What is the angle between <7,2,3> and <8,6,0>?

1 Answer
Apr 19, 2016

approximately 0.528 radians or 30.28

Explanation:

The angle, θ, between two vectors u and v
is such that
XXXcos(θ)=uv||u||||v||

For
XXXu=<u1,u2,u3>=<7,2,3>
and
XXXv=<v1,v2,v3>=<8,6,0>

uv=u1v1+u2v2+u3v3
XXx=7×8+2×6+(3)×0=68

||u||=u21+u22+u23
XXx=72+22+(3)2=62

||v||=v21+v22+v23
XXx=82+62+02=100=10

Therefore
XXXcos(θ)=681062
XXXXXXX0.863601 (using a calculator)
and
XXXθ=arccos(0.863601)0.528426 (radians)