Define Rational Number
Define Rational Number
A rational number is a number that can be expressed as a fraction or ratio. The numerator and the
denominator of the fraction are both integers.When the fraction is divided out, it becomes terminating
or repeating decimal. The repeating decimal portion may be one number or a billion numbers.Rational
numbers can be ordered on a number line.An irrational number cannot be expressed as a
fraction.Irrational numbers cannot be represented as terminating or repeating decimals.Real and
imaginary numbers make up the number system of algebra. Imaginary numbers are discussed in
chapter 15 of this course. Real numbers are either rational or irrational.
The word RATIONAL comes from the word "ratio." A number is rational if it can be expressed as the
quotient, or ratio, of two whole numbers. In mathematics, a rational number is any number that can be
expressed as the quotient or fraction p/q of two integers, with the denominator q not equal to zero.
Since q may be equal to 1, every integer is a rational number. The set of all rational numbers is usually
denoted by a boldface Q (or blackboard bold , Unicode Q), which stands for quotient.The decimal
expansion of a rational number always either terminates after a finite number of digits or begins to
repeat the same finite sequence of digits over and over.Moreover, any repeating or terminating
decimal represents a rational number. These statements hold true not just for base 10, but also for
binary, hexadecimal, or any other integer base.A real number that is not rational is called irrational
Know More About :- Linear Pair of Angles


Math.Edurite.com
Page : 1/3

---

Moreover, any repeating or terminating decimal represents a rational number. These statements hold
true not just for base 10, but also for binary, hexadecimal, or any other integer base.A real number that
is not rational is called irrational. Irrational numbers include 2, , and e. The decimal expansion of an
irrational number continues forever without repeating. Since the set of rational numbers is countable,
and the set of real numbers is uncountable, almost all real numbers are irrational.
The rational numbers can be formally defined as the equivalence classes of the quotient set (Z x (Z

{0})) / ~, where the cartesian product Z x (Z
{0}) is the set of all ordered pairs (m,n) where m and n
are integers, n is not zero (n 0), and "~" is the equivalence relation defined by (m1,n1) ~ (m2,n2) if,
and only if, m1n2 - m2n1 = 0.In abstract algebra, the rational numbers together with certain operations
of addition and multiplication form a field. This is the archetypical field of characteristic zero, and is
the field of fractions for the ring of integers. Finite extensions of Q are called algebraic number fields,
and the algebraic closure of Q is the field of algebraic numbers.
In mathematical analysis, the rational numbers form a dense subset of the real numbers. The real
numbers can be constructed from the rational numbers by completion, using Cauchy sequences,
Dedekind cuts, or infinite decimals.The term rational in reference to the set Q refers to the fact that a
rational number represents a ratio of two integers. In mathematics, the adjective rational often means
that the underlying field considered is the field Q of rational numbers. Rational polynomial usually, and
most correctly, means a polynomial with rational coefficients, also called a "polynomial over the
rationals". However, rational function does not mean the underlying field is the rational numbers, and a
rational algebraic curve is not an algebraic curve with rational coefficients.
Real numbers and topological properties:-The rationals are a dense subset of the real numbers: every
real number has rational numbers arbitrarily close to it. A related property is that rational numbers are
the only numbers with finite expansions as regular continued fractions.By virtue of their order, the
rationals carry an order topology. The rational numbers, as a subspace of the real numbers, also carry a
subspace topology. The rational numbers form a metric space by using the absolute difference metric
d(x,y) = |x - y|, and this yields a third topology on Q. All three topologies coincide and turn the
rationals into a topological field. The rational numbers are an important example of a space which is not
locally compact.
Read More About :- Parallelogram Properties


Math.Edurite.com
Page : 2/3

---

ThankYou
Math.Edurite.Com

---

Document Outline

• 
• ﾿

---