Mathematica usually pays no attention to whether variables like x stand for real or complex numbers. Sometimes, however, you may want to make transformations which are ...
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, ...]. ...
PolynomialQuotient[p, q, x] gives the quotient of p and q, treated as polynomials in x, with any remainder dropped.
DSolve can be used for finding the general solution to a differential equation or system of differential equations. The general solution gives information about the structure ...
Majority[e_1, e_2, ...] gives True if the majority of the e_i are True, and False if the majority are False.
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 ...
WignerD
(Built-in Mathematica Symbol) WignerD[{j, m_1, m_2}, \[Psi], \[Theta], \[Phi]] gives the Wigner D-function D_m_1^m_2, j(\[Psi], \[Theta], \[Phi]).WignerD[{j, m_1, m_2}, \[Theta], \[Phi]] gives the Wigner ...
InverseFourierTransform[expr, \[Omega], t] gives the symbolic inverse Fourier transform of expr. InverseFourierTransform[expr, {\[Omega]_1, \[Omega]_2, \ ...}, {t_1, t_2, ...
ComplexExpand[expr] expands expr assuming that all variables are real. ComplexExpand[expr, {x_1, x_2, ...}] expands expr assuming that variables matching any of the x_i are ...
Erf
(Built-in Mathematica Symbol) Erf[z] gives the error function erf(z). Erf[z_0, z_1] gives the generalized error function erf(z_1) - erf(z_0).