Radical Integer
A radical integer is a number obtained by closing the Integers under Addition, Division,Multiplication, Subtraction, and Root extraction. An example of such a number is 
. The radical integers are a subring of the AlgebraicIntegers. If there are Algebraic Integers which are not radical integers,they must at least be cubic.
- Rectangular Projection
- Rectifiable Current
- Rectifiable Set
- Rectification
- Rectifying Latitude
- Rectifying Plane
- Recurrence Relation
- Recurrence Sequence
- Recurring Digital Invariant
- Recursion
- Recursive Function
- Recursive Monotone Stable Quadrature
- Red-Black Tree
- Red Net
- Reduced Amicable Pair
- Reduced Fraction
- Reduced Latitude
- Reducible Crossing
- Reducible Matrix
- Reducible Representation
- Reduction of Order
- Reduction Theorem
- Redundancy
- Reeb Foliation
- Reef Knot