O
(Built-in Mathematica Symbol) O[x]^n represents a term of order x^n. O[x]^n is generated to represent omitted higher-order terms in power series. O[x, x_0]^n represents a term of order (x - x_0) n.
QHypergeometricPFQ[{a_1, ..., a_r}, {b_1, ..., b_s}, q, z] gives the basic hypergeometric series \[Null]_r \[Phi]_s (a; b; q; z).
Range
(Built-in Mathematica Symbol) Range[i_max] generates the list {1, 2, ..., i_max}. Range[i_min, i_max] generates the list {i_min, ..., i_max}. Range[i_min, i_max, di] uses step di.
Short
(Built-in Mathematica Symbol) Short[expr] prints as a short form of expr, less than about one line long. Short[expr, n] prints as a form of expr about n lines long.
SplineKnots is an option for B-spline functions and graphics primitives that specifies the positions of knots.
SplineWeights is an option for B-spline functions and graphics primitives that specifies weights of control points.
Sqrt
(Built-in Mathematica Symbol) Sqrt[z] or Sqrt[z] gives the square root of z.
NIntegrate[f, {x, x_min, x_max}] gives a numerical approximation to the integral \[Integral]_x_min^x_max\ f\ d \ x. NIntegrate[f, {x, x_min, x_max}, {y, y_min, y_max}, ...] ...
DiscreteRatio[f, i] gives the discrete ratio f(i + 1)/f(i).DiscreteRatio[f, {i, n}] gives the multiple discrete ratio.DiscreteRatio[f, {i, n, h}] gives the multiple discrete ...
If you make a definition like f[x_]:=x Sin[x], Mathematica will store the expression x Sin[x] in a form that can be evaluated for any x. Then when you give a particular value ...