TrigReduce[expr] rewrites products and powers of trigonometric functions in expr in terms of trigonometric functions with combined arguments.
LogGamma[z] gives the logarithm of the gamma function log \[CapitalGamma](z).
SquareFreeQ[expr] gives True if expr is a square-free polynomial or number, and False otherwise.SquareFreeQ[expr, vars] gives True if expr is square free with respect to the ...
HypergeometricPFQ[{a_1, ..., a_p}, {b_1, ..., b_q}, z] is the generalized hypergeometric function \[Null]_p F_q (a; b; z).
lhs := rhs assigns rhs to be the delayed value of lhs. rhs is maintained in an unevaluated form. When lhs appears, it is replaced by rhs, evaluated afresh each time.
Mathematica 's rich syntax uses different kinds of brackets and braces; familiarity with these aspects lets you read and program efficiently in Mathematica .
Weights
(Built-in Mathematica Symbol) Weights is an option for various fitting and other functions which specifies weights to associate with data elements.
Denominator[expr] gives the denominator of expr.
Numerator[expr] gives the numerator of expr.
PolynomialRemainder[p, q, x] gives the remainder from dividing p by q, treated as polynomials in x.