ProgressIndicator[x] represents a progress indicator with setting x in the range 0 to 1. ProgressIndicator[Dynamic[x]] takes the setting to be the dynamically updated current ...
Quartics is an option for functions that involve solving algebraic equations that specifies whether explicit forms for solutions to quartic equations should be given.
Rational is the head used for rational numbers.
Reals
(Built-in Mathematica Symbol) Reals represents the domain of real numbers, as in x \[Element] Reals.
ReflectionMatrix[v] gives the matrix that represents reflection of points in a mirror normal to the vector v.
Rescale
(Built-in Mathematica Symbol) Rescale[x, {min, max}] gives x rescaled to run from 0 to 1 over the range min to max. Rescale[x, {min, max}, {x_min, x_max}] gives x rescaled to run from x_min to x_max over ...
RootOfUnityQ[a] yields True if a is a root of unity, and yields False otherwise.
RotationTransform[\[Theta]] gives a TransformationFunction that represents a rotation in 2D by \[Theta] radians about the origin.RotationTransform[\[Theta], p] gives a 2D ...
ScalingMatrix[{s_x, s_y, ...}] gives the matrix corresponding to scaling by a factor s_i along each coordinate axis.ScalingMatrix[s, v] gives the matrix corresponding to ...
SetAttributes[s, attr] adds attr to the list of attributes of the symbol s.