# Derivatives of fields

1. Apr 10, 2014

### Jhenrique

Given a vector field f, I can compute the rotational tendency in the direction n (×f·n), the translational tendency in the direction t (∇f·t) and the divergence (·f) too. So, given a scalar field f, why I can compute only the directional derivative (translational tendency (t)) in the wanted direction?

2. Apr 10, 2014

### chogg

Because what would it even mean for a scalar field to have a rotational tendency, or to diverge?