Hello friends, I am having trouble with part d of this question, any help would be appreciated!
8. The cube OABCDEFG has vertices O(0, 0, 0), A(a, 0, 0), B(a, a, 0), C(0, a, 0), D(0, a, a), E(0, 0, a), F(a, 0, a) and G(a, a, a), where a > 0.
(a) Use a scalar product to find the angle between...