real coordinate space

In mathematics, real coordinate space of  dimensions, written R ( ) (R with superscript n, also written with blackboard bold R) or R^n with keyboard is a coordinate space that allows several () real variables to be treated as a single variable. With various numbers of dimensions (sometimes unspecified), is used in many areas of pure and applied mathematics, as well as in physics. It is the prototypical real vector space and a frequently used . Due to the latter fact, geometric metaphors are widely used for , namely a plane for and three-dimensional space for .