Chao Wang, Guangzhou Qin, Ravi P. Agarwal

Generalized Directional Derivatives and Gradient of Multivariate Function on Time Scales

abstract:
In this paper, we introduce a notion of jump operators along the assigned direction $\vec{\omega}$ and the corresponding opposite direction $-\vec{\omega}$ on an $n$-dimensional time scale $\Lambda^{n}$, due to which the total increment of the multivariate function can be represented accurately. Based on it, we introduce the new notions of directional derivatives and gradient of multivariate function on time scales and demonstrate their nice geometric significance. Moreover, some basic results are established which improve and perfect the previous literature.

Mathematics Subject Classification: 26E70, 34N05

Key words and phrases: Time scale, jump operators along the assigned direction, directional derivative, gradient, partial derivative