Page 42 - Mathematics Class - XII
P. 42

ACTIVITY 3.4






        OBJECTIVE

        To verify that for a function f to be continuous at given point x , Δ y = | f (x  + Δ x) – f (x ) | is arbitrarily small
                                                                                               0
                                                                                  0
                                                                      0
        provided Δ x is sufficiently small.
        MATERIAL REQUIRED

         Y   Cardboard                                          Y  Scale
         Y  Graph paper                                         Y  Calculator
         Y  Pencil                                              Y  Adhesive


        PRE-REQUISITE KNOWLEDGE
            1.  Knowledge of the concept of the continuity of a function.


        PROCEDURE
            1.  Take cardboard and paste a graph paper on it.

            2.  Draw the curve of any continuous function y = f(x) as represented in the Fig. (a).
            3.  Take a point A(1, 0) on the positive side of x-axis and corresponding to this point, mark the point P(1, 1.4)
               on the curve.


                      Y Y








                    2 2
                                                                                               y y =( )fx=( )fx
                                                                            N 1 N 1
                                                                      N 2 N 2
                                                                N 3 N 3
                                                          N 4 N 4
                                                    N 5 N 5             y      y
                                                                               y 11
                                                                        y 22
                                                                  y 33
                                                            y     y
                                                            y 44
                                                          y
                                                          y 55
                                                  P(1, 1.4)
                                                  P(1, 1.4)
                                                             T 4 T 4  T 3 T 3  T 2 T 2  T 1 T 1
                    1 1
                                                                              (1.8, 0)
                                               (1, 0) AA
                                               (1, 0)                         (1.8, 0)
                  X´
                  X´                                                                                    X X
                     O O                             1 1                           2 2
                      Y´
                      Y´                            M     M     M     M     M
                                                    M 55
                                                          M 44
                                                                M 33
                                                                            M 11
                                                                      M 22
                                                                 = 0.8
                                                                x 1 = 0.8x 1
                                                           Fig. (a)
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