Mathematics

Problem

The angle between the lines

AB

and

CD

, where

A = (0, 0, 0)

B = (1, 1, 1)

C = (-1, -1, -1)

and

D = (0, 1, 0)

is given by a.

\cos \theta = \frac{1}{\sqrt{3}}

\cos \theta = \frac{4}{3\sqrt{2}}

\cos \theta = \frac{1}{\sqrt{5}}

\cos \theta = \frac{1}{2\sqrt{2}}