- Raabe's test - see Series - Theory - Testing convergence - More tests
- radians, introduction - see this note
- radius of convergence of power series - see Series - Theory - Series of functions - Power series and Series - Methods Survey - Series of functions - Power series
- range
*R*(*f*) of a function - see Functions - Theory - Real functions - Introduction - range
*R*(*T*) of a mapping - see Extra - Sets and mappings - Mappings - Ratio test - see Series - Theory - Testing convergence - Root and Ratio test and Series - Methods Survey - Testing convergence - Ratio test, see also this note
- Ratio test for general series - see Series - Theory - Testing convergence - Convergence of general series
- rational function
- rational numbers - see Extra - Sets and mappings - Important sets of numbers
- rational numbers, countable - see Extra - Sets and mappings - Mappings
- real function - see functions
- real numbers - see Extra - Sets and mappings - Important sets of numbers
- real numbers, extended - see Functions - Theory - Real numbers - Intervals and neighborhoods
- real numbers, uncountable - see Extra - Sets and mappings - Mappings
- recursive definition of a sequence - see Sequences - Theory - Introduction - Introduction
- reduced neighborhood - see Functions - Theory - Real numbers - Intervals and neighborhoods
- reduction formula for integral of rational function - see Integrals - Methods Survey - Methods of integration - Partial fractions
- reduction formula for integral of trig functions - see Integrals - Methods Survey - Methods of integration - Trig integrals
- reflexivity - see Extra - Sets and mappings - Important sets of numbers
- region of (absolute) convergence of power series - see Series - Theory - Series of functions - Power series and Series - Methods Survey - Series of functions - Power series
- region of (absolute) convergence of sequence of functions - see Series - Theory - Series of functions - Sequences of functions and Series - Methods Survey - Series of functions - Sequences of functions
- region of (absolute) convergence of series of functions - see Series - Theory - Series of functions - Series of functions and Series - Methods Survey - Series of functions - Series of functions
- reindexing series - see Series - Theory - Introduction - Introduction
- related rates - see Derivatives - Theory - Applications - Related rates and Derivatives - Methods Survey - Applications - Related rates
- remainder of Taylor polynomial - see Derivatives - Theory - Applications - Taylor polynomial
- removable discontinuity - see continuity
- reordering of series - see Series - Theory - Introduction - Basic properties and Series - Theory - Introduction - Absolute convergence
- restriction of a function - see Functions - Theory - Real functions - Introduction
- restriction of a mapping - see Extra - Sets and mappings - Mappings
- Riemann integral - see Integrals - Theory - Introduction -Riemann integral
- right neighborhood - see Functions - Theory - Real numbers - Intervals and neighborhoods
- Rolle's theorem - see Derivatives - Theory - MVT - MVT and comp.
- root as a function - see power
- root as a number - see Functions - Theory - Elementary functions - Powers
- root of a function
- Root test - see Series - Theory - Testing convergence - Root and Ratio test and Series - Methods Survey - Testing convergence - Root test, see also this note
- Root test for general series - see Series - Theory - Testing convergence - Convergence of general series
- rule