I've attached the .pdf from which I have questions. After it says "Take the square of the numerator" halfway down the page, there is an equation that lists vector components with hats and arrows at the same time, and the arrow on other vectors. Can someone help explain the difference to me? I had though hats denoted vector components, but I don't think you can take the dot product of a component and a full vector. Please correct me if I'm wrong!