Radian
A unit of measurement
of angles.
Radical
The symbol
is called nradical, in particular, the square radical is
usually written as.
Radical
expression
An expression
written with a radical is called a radical expression.
Radicand
The expression
written under the radical is called the radicand.
Radius
A line segment
joining the center of a circle or sphere to any point on its circumference.
Range
The set of values
that a given function takes as its argument varies through its domain
Ratio
Quotient of
two quantities or expressions.
Rational
number
Any number that
can be expressed as a ratio of two integers with nonzero denominator.
Rational
function
Any quotient
of two polynomials with nonzero denominator.
Ray
A half line
extending from a point.
Real
line
A number line
with every point assigned a real number on it.
Real
variable
A variable that
ranges over a set of real numbers.
Reciprocal
Relating to
a multiplicative inverse by interchange the numerator and the denominator
of a number and the product of a number and its reciprocal is 1.
Rectangle
A parallelogram
with four right angles.
Rectangular
coordinates
Cartesian Coordinates.
Reduce
To simplify
the form of an expression.
Region
A connected
subset of twodimensional space.
Right
angle
An angle of
90 degrees
Root
A value when
substituted for the variable into an equation will make the equation
a true statement
Round
To approximate
a number to a certain number of significant digits
Rule
A fixed procedure
for solving some problem.
