Tan
(Built-in Mathematica Symbol) Tan[z] gives the tangent of z.
FactorialPower[x, n] gives the factorial power x (n). FactorialPower[x, n, h] gives the step-h factorial power x (n, h).
FactorInteger[n] gives a list of the prime factors of the integer n, together with their exponents. FactorInteger[n, k] does partial factorization, pulling out at most k ...
Indeterminate is a symbol that represents a numerical quantity whose magnitude cannot be determined.
LaplaceTransform[expr, t, s] gives the Laplace transform of expr. LaplaceTransform[expr, {t_1, t_2, ...}, {s_1, s_2, ...}] gives the multidimensional Laplace transform of ...
Mod
(Built-in Mathematica Symbol) Mod[m, n] gives the remainder on division of m by n. Mod[m, n, d] uses an offset d.
PowerExpand[expr] expands all powers of products and powers. PowerExpand[expr, {x_1, x_2, ...}] expands only with respect to the variables x_i.
QPochhammer[a, q, n] gives the q-Pochhammer symbol (a; q) n.QPochhammer[a, q] gives the q-Pochhammer symbol (a; q) \[Infinity].QPochhammer[q] gives the q-Pochhammer symbol ...
RootReduce[expr] attempts to reduce expr to a single Root object.
StringCases["string", patt] gives a list of the substrings in " string" that match the string expression patt. StringCases["string", lhs -> rhs] gives a list of the values of ...