Are you sure about your Dot Product?

I always skim read the dot product module of my calculus course. Never really paying attention to its meaning. Another thing that has become a habit due to my laziness is that I read the solutions to math questions without actually practising them…

Not going to bore you more by actually trying to explain to you the concept of the Dot Product and fail at it. Since, I still might not have understood it.

However, I like tricking people with math puzzles. The following one can come in quite handy. So this is how the problem goes: