Writhe the component of ` vec b` along ` vec adot`

Explanation

Component of `vec{b}` on `vec{a}` is


`{frac{vec{a} cdot vec{b}}{|a|}} hat{a}`


`={frac{(vec{a} cdot vec{b})}{|vec{a}|^{2}}} vec{a}`


`=frac{(vec{a} cdot vec{b}) vec{a}}{|vec{a}|^{2}}`