Irrational numbers are numbers that cannot be written as a fraction involving two integers. For instance, if "a" is an integer and "b" is an integer, an irrational number is a number that cannot be expressed as a fraction "a/b".
The main feature of irrational numbers is that they have a non-repeating and non-terminating decimal. This means that there is no pattern and no end to the right .
of the decimal place when written in decimal notation.
The most famous irrational number is the number pi. Pi is unable to be represented by a fraction, and therefore it is irrational. An approximation of pi to the fifth decimal place is 3.14159..., and it is commonly approximated as the fraction 22/7. These are both merely approximations because pi cannot be expressed as a fraction and its decimal never ends.
More Reference Links: http://www.wtamu.edu/academic/anns/mps/math/mathlab/beg_algebra/beg_alg_tut2_sets.htm http://www.jcu.edu/math/vignettes/sqrt2.htm
