Skip to main content

LIMITLESS LEADS TO LIMIT - The birth of calculus



If you go on increase the number of  sides of a polygon. the circle will be the limit.


     1/2^1 + 1/2^2 + 1/2^3 + 1/2^4+........  =1
                           or
     Sum of all the terms of 1/2^n  = 1

     When n goes from 1 to infinity, the sum of the above series approaches 'one'; but never touches 'one' or crosses 'one', however bigger the 'n' may be.  Hence we can say, the limit of the sum of the series is 1.

(1+1/1)^1+ (1+1/2)^2 +(1+1/3)^3 + .....     =2.71... = e
The limit of the above series is the famous Euler constant e.

    The concept of limit is the corner stone of calculus.  Let us see an example.
Let y= x^2
Let dx be the smallest change in x , let dy be the corresponding small change in y.
I want to find dy/dx
Let x be 3, let the small change be 0.1 (dx) The new x is 3.1
corresponding change in y is

                           y=x^2
      old x: 3        9
     new x: 3.1    9.61

hence   dy = 9.61 - 9 = .61
dy/dx = 0.61/0.1 = 6.1
Now  let us give still more small change in x, that is 0.01
                           y=x^2
      old x: 3         9
     new x: 3.01    9.0601
  
Now dy = 9.0601 - 9 = 0.0601
again, dy/dx = 0.0601/0.01 = 6.01

   If we go on give more and more smaller change in 'x' (like .01,.0033,.0001), the dy/dx will approach 6(the limit).  Since x = 3; 6 = 2x.  Hence dy/dx =2x
That is small change in y divided by small change in x yields 2x whatever may be the value of x.
     This is the operation 'division' for continuous functions like growth of a plant, fall of temperature, increase of electric current.  We call this operation as "differentiation".  That is calculus.
     The ordinary 'division' is applicable to only countable things like books, pens, chocolates etc.

Note: 1. if y=sinx
              dy/dx = cosx
           2. If y = x^3
              dy/dx = 3x^2   
           3. If y= 5x
              dy/dx =5    and on and on
The above are proved results from calculus.

Comments

Popular posts from this blog

THE EARTH, A SUPER ORGANISM

     JOIN MY COURSE: "Become a programmer in a day with python"       A man called 'love lock' (what a name) proposed a theory called Gaia theory, named after Greek Goddess.      It says, "Earth is a self-regulating organism like a human being.  The organic life in it interacts with in-organic matter and maintains atmosphere, temperature and environment".  Hence the earth is still suitable for the life to thrive.      Imagine, in a particular place, there are lot of flowers.  Some flowers are white and some are darkly coloured.  We know, white reflects light and heat while dark absorbs the same.  White flowers can thrive in hot climate.  But dark flowers requires cold climate.  The absorption and reflection balances and the environment reaches average, warm temperature at which both the flowers can co-exist.  This is the essence of "Gaia" theory.      On our earth, ...

THE PARABOLA

          A jet of water shooting from a hose pipe will follow a parabolic path.  What is the so special about parabola.    Y= x^2 Draw a graph for the above equation.  It will result in a parabola.  This parabola is also called unit parabola.  Any equation involving square will yield a parabola. Example:  Y = 2x^2 +3x+3 (also called quadratic equation)    X= 2 and -2, both  satisfies the equation 4 = X^2.  Parabolic equations always have two solutions.     Any motion taking place freely under gravity follows parabolic path. Examples:   An object dropped from a moving train,   A bomb dropped from flying plane,  A ball kicked upwards.      If a beam of light rays fall on the parabolic shaped mirror, they will be reflected and brought to focus on a point.  This fact is made use of in Dish Antenna, Telescope mirrors, etc.   ...

DISORDER IS THE "ORDER OF THE DAY"

         Imagine a balloon full of air.  The air molecules are moving randomly inside the balloon.  Let us pierce the balloon with a pin.  The air rushes out.  Why should not the air molecules stay inside the balloon safely and ignore the little hole?  That is not the way the world works.  The molecules always "want to occupy as many states as possible".  Hence the air goes out in the open to occupy more volume.   The things always goes into disorder (entropy) and the disorder increases with time.  The above statement is what we call "second law of thermodynamics".      Consider a cup of coffee on the table. Suppose the heat from entire room flows to your cup of coffee, the coffee will boil and the rest of the room will freeze.  Freezing means bringing things to order and arrangement.  It violates the second law.  Hence it will never happen.  Hence heat must flow from high ...