Question

For any unit vectors v and w on R, find the dot products of v+w and v-w

Answer 1

FOIL seems to work well here...

Answer 2

FOIL?

Answer 3

FOIL, like when you multiply binomials.

Answer 4

so it's simply v^2+w^2?

Answer 5

easy with the signs...

Answer 6

and be careful, there is no such thing as "squaring" a vector.
\[\Large \vec v \cdot \vec v - \vec w \cdot \vec w\]

Answer 7

Oh right! thanks