AiryBiPrime[z] gives the derivative of the Airy function Bi^\[Prime] (z).
Animator[u] represents an object that displays with the value of u being continually increased from 0 to 1 with time. Animator[u, {u_min, u_max}] makes u vary from u_min to ...
Apply
(Built-in Mathematica Symbol) Apply[f, expr] or f @@ expr replaces the head of expr by f. Apply[f, expr, {1}] or f @@@ expr replaces heads at level 1 of expr by f.Apply[f, expr, levelspec] replaces heads ...
Arg
(Built-in Mathematica Symbol) Arg[z] gives the argument of the complex number z.
Array
(Built-in Mathematica Symbol) Array[f, n] generates a list of length n, with elements f[i]. Array[f, {n_1, n_2, ...}] generates an n_1*n_2*... array of nested lists, with elements f[i_1, i_2, ...]. ...
ArrayRules[SparseArray[...]] gives the rules {pos_1 -> val_1, pos_2 -> val_2, ...} specifying elements in a sparse array. ArrayRules[list] gives rules for SparseArray[list].
Background is an option that specifies what background color to use.
BaselinePosition is an option that specifies where the baseline of an object is considered to be for purposes of alignment with surrounding text or other expressions.
BenfordDistribution[b] represents a Benford distribution with base parameter b.
BernoulliGraphDistribution[n, p] represents a Bernoulli graph distribution for n-vertex graphs with edge probability p.