Positive real numbers
Subset of real numbers that are greater than zero / From Wikipedia, the free encyclopedia
In mathematics, the set of positive real numbers, is the subset of those real numbers that are greater than zero. The non-negative real numbers,
also include zero. Although the symbols
and
are ambiguously used for either of these, the notation
or
for
and
or
for
has also been widely employed, is aligned with the practice in algebra of denoting the exclusion of the zero element with a star, and should be understandable to most practicing mathematicians.[1]
In a complex plane, is identified with the positive real axis, and is usually drawn as a horizontal ray. This ray is used as reference in the polar form of a complex number. The real positive axis corresponds to complex numbers
with argument