Skip to main content

BASIC CONCEPTS AND COMPLEX NUMBERS


                               BASIC CONCEPTS

                       AND COMPLEX NUMBERS

               We begin by describing some intuitive ideas about sets.

              A collection of objects under a rule or a property is call a set,
The underlying rule or property will determine, Whether the given object belongs to the collection or not.  The objects which belong to a set are called its members or elements or occasionally its points.

              The theory of sets has been systematically studied only since about 1880, when  G. Cantor formulated the basic definitions and axioms.

              He remarked that a set must consists of definite , "well defined" elements, that is to say If we have in mind some particular collection then we call it a "set" if, given any object we can decide whether it belongs to the collection we are interested in or whether it, doses not. This seemingly obvious property is violated by some objects, we can illustrate this by an example due to Bertrand Russell. Suppose we have a set of letters (alphabets), we call it S, then since S is itself an object, either S will not belong to (the set) S.

               We therefore, see that there are pitfalls in a deep study of set theory. We   shall take it as an axiom that sets do exist and they contain well defined objects.

                The reader may feel that this is in some sense cheating. Let us look at the problem of language. If we look up a word in a dictionary, its meaning is given using other words.

             For instance, take the word "Straight", According to the dictionary, This means "Without bend", so we look up "bend" ; a "bend" is defined to be a "curve" and upon looking up "curve", We see that it is 'a line no part of which is straight" . If we put all these definitions together,We see that we obtain a circular definition ."straight" means "straight".

             We adopt the same viewpoint here that a set is what we would intuitively think of as a collection of objects some.

Comments

Popular posts from this blog

THERMAL PROPERTIES

THERMAL PROPERTIES OF METER  The crocus flower is a natural thermometer. It opens when the temperature is precisely 23 degree centigrade and closes when the temperature drops. Liquid in Glass Thermometer Construction: A liquid in glass thermometer has a bulb whit a log capillary tube of uniform and fine bore. PRINCIPLE      Liquid in glass thermometer is made on he principle of expansion of heating.       A suitable liquid is filed in the bulb. When  we touch the bulb with a hot body, the liquid in it expands and rises in the tube. the glass stem of a thermometer is thick and acts as a cylindrical lens. This makes it easy to see the liquid lever in the glass tube. THE MERCURY IN GLASS THERMOMETERS\ Mercury freezes at -39 degree centigrade and boils at 357 degree centigrade. Mercury has all the thermometer properties. So mercury is one of the most suitable thermometer materials. Murcury in glass thermometer are widely used in laboratories, clinic and house to measure tempertatures in th

HEAT AND THERMODYNAMICS

U                        HEAT AND THERMODYNAMICS        Thermodynamics deals with various phenomena of energy and related properties of matter, especially the transformation of heat into other forms of energy. An example of such transformation is the process converting heat into mechanical work. Thermodynamics thus plays central role in technology, since almost all the raw energy available for our use is liberated in the form of heat. in this topic we shall their significance and applications.               KINETIC THEORY OF GASES       The behavior of gases is well accounted for by the kinetic theory based on microscopic approach. Evidence in favor of the theory is exhibited in diffusion of gases and Brownian motion of smoke particles etc.      The following postulates help to formulate a mathematical model of gases.      A finite volume of gas consists of very large number of molecules.      The size of the molecules is much smaller then the separation between molecules.

TIME SERIES ANALYSIS

Introduction                 A time series consists of numerical data collected observed or recorded at more or less regular intervals of time each hour, day, month, quarter or year, More specifically, it is any set of data in which observation are arranged in a chronological order, Examples of time series are the hourly temperature recorded at a locality for a period of year, the weekly prices of wheat in Lahore, the monthly consumption of electricity in a certain town, the monthly total of passengers carried by rial,the quarterly sales of a certain fertilizer, the annual rainfall at Karachi for a number of year, the enrollment of students in a college or university over a number of year and so forth.               The analysis of a time series is a process by which a set of observation in a time series in analyses.Time series analysis is rather a difficult topic but we shall limit our discussion to the basics of time series analysis          The observation in a time series, d