JacobiCD[u, m] gives the Jacobi elliptic function cd(u | m).
JacobiCS[u, m] gives the Jacobi elliptic function cs(u | m).
JacobiDC[u, m] gives the Jacobi elliptic function dc(u | m).
KleinInvariantJ[\[Tau]] gives the Klein invariant modular elliptic function J(\[Tau]).
LucasL
(Built-in Mathematica Symbol) LucasL[n] gives the Lucas number L_n.LucasL[n, x] gives the Lucas polynomial L_n (x).
ShearingMatrix[\[Theta], v, n] gives the matrix corresponding to shearing by \[Theta] radians along the direction of the vector v, and normal to the vector n.
SymmetricPolynomial[k, {x_1, ..., x_n}] gives the k\[Null]^th elementary symmetric polynomial in the variables x_1, ..., x_n.
ThreeJSymbol[{j_1, m_1}, {j_2, m_2}, {j_3, m_3}] gives the values of the Wigner 3-j symbol.
ToContinuousTimeModel[sys] gives the continuous-time approximation of the discrete-time TransferFunctionModel or StateSpaceModel object sys.ToContinuousTimeModel[tf, s] gives ...
TransferFunctionCancel[tf] cancels common poles and zeros in the TransferFunctionModel object tf.TransferFunctionCancel[tf, crit] cancels only common pole-zero pairs e_i for ...