Show that the projection or component of a vector `vecR ` on another vector `vecA is vecR*hata`, where `hata` is a unit vector along `vecA`.

Explanation

In general, the component of a vector `vecR` along a direction of another vector making an angle `theta` with it, is R cos `theta` which is the projection of `vecR` along the direction of that vector .
Consider two planes passing through the initial and terminal points of `vecR`, are perpendicular to `vecA` at F and H respectively [Fig.2.80]. Then, projection of `vecR on vecA` is