  In this paper we introduce the concept of \emph{multivector functionals.} We
study some possible kinds of derivative operators that can act in interesting
ways on these objects such as, e.g., the $A$-directional derivative and the
generalized concepts of curl, divergence and gradient. The derivation rules are
rigorously proved. Since the subject of this paper has not been developed in
previous literature, we work out in details several examples of derivation of
multivector functionals.
