![Chapter 1: Sets, Functions and Enumerability](http://s1.studyres.com/store/data/001071338_1-16fe6524c82bcb77aab2480f56e3c029-300x300.png)
Real Numbers and Their Graphs
... The number line continues forever to the left and to the right. Numbers to the left of 0 (the origin) are negative, and numbers to the right of 0 are positive. The number that corresponds to a point on the number line is called the coordinate of that point. For example, the coordinate of the origin ...
... The number line continues forever to the left and to the right. Numbers to the left of 0 (the origin) are negative, and numbers to the right of 0 are positive. The number that corresponds to a point on the number line is called the coordinate of that point. For example, the coordinate of the origin ...
CBSE 8th Class Mathematics Chapter Rational Number CBSE TEST
... (i) The rational number that does not have a reciprocal. (ii) The rational numbers that is equal to their reciprocals. (iii) The rational number that is equal to its negative. (iv) The additive inverse of a negative number 7. Give a rational number which when added to it gives the same number. 8. By ...
... (i) The rational number that does not have a reciprocal. (ii) The rational numbers that is equal to their reciprocals. (iii) The rational number that is equal to its negative. (iv) The additive inverse of a negative number 7. Give a rational number which when added to it gives the same number. 8. By ...
Infinity
![](https://commons.wikimedia.org/wiki/Special:FilePath/Screenshot_Recursion_via_vlc.png?width=300)
Infinity (symbol: ∞) is an abstract concept describing something without any limit and is relevant in a number of fields, predominantly mathematics and physics.In mathematics, ""infinity"" is often treated as if it were a number (i.e., it counts or measures things: ""an infinite number of terms"") but it is not the same sort of number as natural or real numbers. In number systems incorporating infinitesimals, the reciprocal of an infinitesimal is an infinite number, i.e., a number greater than any real number; see 1/∞.Georg Cantor formalized many ideas related to infinity and infinite sets during the late 19th and early 20th centuries. In the theory he developed, there are infinite sets of different sizes (called cardinalities). For example, the set of integers is countably infinite, while the infinite set of real numbers is uncountable.