We'd like to use analytics cookies to understand which symbols people look up, so we know what to research next. They are not used for advertising and we set none of them unless you say yes. What we store.
A subscripted del or a dotted gradient, giving the rate of change along one chosen direction.
Also known as: Directional derivative, Del sub v
A directional derivative asks how fast a function changes if you walk in one particular direction, rather than in the steepest one. It is written either as del with the direction as a subscript or as the gradient dotted with a unit vector, and the second form makes clear that the answer is largest when the direction is the gradient itself.
Denotes the rate of change of a scalar field along a specified direction, written ∇_v f or ∇f · v̂.
Contexts: Mathematics
Requires the direction vector to be a unit vector for the value to be a rate per unit distance; texts that omit the normalisation are computing something scaled.
Contexts: Mathematics
An inverted triangle with a small letter set below and right of it, followed by the name of a function.