Introduction 

A metric space, according to applied mathematical sciences, is a set X together with a function d which assigns a real number d(x,y) to every pair x,yX.

If,

d(x,y)≥0 and d(x,y) ⇔ x=y

d(x,y) = d(y,x)

d(x,y)+d(y,z) ≥d(x,z)

So, a metric is an abstract set with a distance function, and a metric space is a set that is not empty and has a metric on it. According to applied mathematical sciences, the metric is a specific function that describes a distance concept between any two elements of a set, often known as points. The measure meets a few essential criteria:

• If and only if A and B are the same point, the distance between them is 0.
• The difference in distance between two distinct points is positive.
• The distance between A and B is the same as the distance between B and A.
• The distance between A and B is less than or equal to the distance between A and B via any third location C.

According to the research in mathematical sciences, Topological features, such as open or closed sets, are created by a metric applied to a space, giving rise to spaces of abstract topology.

The most well-known metric space in Mathematical Sciences is three-dimensional Euclidean space. A “metric” is a generalization of the Euclidean metric derived from the four well-known properties associated with Euclidean distance. In the Euclidean metric, the length of a straight-line segment connecting two points is defined as the distance between them. Other metric spaces may be found in elliptic and hyperbolic geometry, where angle-defined distance on a sphere is a metric, and special relativity employs the hyperboloid model of hyperbolic geometry as a metric space of velocities in Mathematical Sciences.

Historical remarks 

As the need for a new system grew during the French Revolution, the first practical use of the metric system occurred in 1799. This system quickly surpassed the kilogram and meter systems. The method of metric spaces in Mathematical Sciences then became the standard in France and Europe within a half-century. Other metrics based on unity ratios were added, and the system was finally accepted globally.

Example:

1. If X is a set and M is a metric space, the set of all bounded functions f:X M (i.e, those whose image is a bounded subset of M) may be transformed to a metric space by defining  d(f,g) = supxX  d(f(x),g(x)). (here, sup is supremum). This is known as the uniform or supremum metric in Mathematical Sciences, and if M is complete, then this function space is as well. 
2. Rn endowed with the Euclidean distance,

d(x,y)=(i=1n(xi–yi)2)1/2

is a metric space. Unless otherwise specified, Rn will always be assumed to be endowed with the Euclidean metric.

1. Let F ∶ R → R be any strictly monotonic function (say increasing). Then, R endowed with the distance function.

D (x, y) = ∣F(x) − F(y)∣ 

Is a metric space. Symmetry and positivity are immediate. It only remains to verify the triangle inequality. For x,y,z∈ R,

d(x,z)=F(x)-F(z)

F(x)-F(z)+F(y)-F(z)

=d(x,y)+d(y,x)

It’s worth noting that F’s tight monotonicity is simply required to verify that d is positive.

1. The earth’s surface is a metric space in Mathematical Sciences, with d being the (shortest) distance between great circles.
2. Any non-empty set X can be endowed with the discrete metric in Mathematical Sciences.

d(x,y)=0 ,for  x=y

And 1, for xy.

This is a particularly dull statistic since it gives no information on the structure of the space. We will, however, regularly utilize it as a clarifying example. It’s worth mentioning that the discrete and continuous metrics are interchangeable. We can apply the graph metric if we provide X with the structure of a whole graph.

Normed Spaces- a subsection of metric spaces

In many applications of the journal of mathematical sciences, on the other hand, metric space has a metric derived from a norm that determines the “length” of a vector. We can refer to normed linear spaces as normed vector spaces, or rather as a vector space X endowed with a norm. For example, n-dimensional Euclidean space is a normed linear space (after a point is chosen as the origin).

Suppose X be a vector space over R (taking in consideration that the Vector spaces are over C as well). A norm on X is a function ∥ ⋅ ∥ ∶ X → R satisfying the following rules:

1. Positivity: ∥x∥ ≥ 0   ⇔  x=0
2. Homogeneity: for all x ∈ X and aR ,∥ax∥ = ∣a∣∥x∥
3. The triangle inequality: for all x,y  ∈ X,

∥x + y∥ ≤ ∥x∥ + ∥y∥

Conclusion

A metric space is a set containing a distance function that may be used to calculate the distance between any two points in the set. A collection of axioms must be satisfied by the distance function, often known as a metric. One is a metric space S, and the other is a pair of metrics d (S,d).