6.4
New Generation Textbooks
The textbooks discussed above first appeared in the 1970s or 1980s.
Below, we briefly describe certain textbooks that appeared and became
popular significantly later.
6.4.1
The textbook of A. G. Mordkovich and
I. M. Smirnova
The textbooks of Mordkovich and Smirnova (2009a, 2009b) conclude
the series of textbooks by Mordkovich for grades 7–9. Their textbook
is in many respects intended for independent work. “Each paragraph
contains a detailed and comprehensive presentation of theoretical
material, addressed directly to students” (Mordkovich and Smirnova,
2009a; p. 3). Each paragraph is accompanied by a large number of
exercises; thus, there is enough material for both classroom work and
work at home.
The textbook’s central concept is the mathematical model. For
example, the derivative is introduced as follows. After examining two
problems that are standard in this situation — one on instantaneous
velocity and one on tangents — the authors state:
Two different problems have led us to the same mathematical
model — the limit of the ratio between the change in a function
and the change in its argument, on the condition that the change in
the argument approach zero. . . . This mathematical model, then, is
what should be studied. That is:
(a) It should be given a formal definition and labeled with a new
term;
(b) New notation should be introduced for this model;
(c) The properties of this new model should be investigated.
(Mordkovich and Smirnova, 2009a; p. 232)
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The distinctive feature of the presentation of the topic “Derivatives”
in this textbook consists in the fact that it begins with the presentation
of the limit of a sequence. This concept is defined in the language
of “neighborhoods” and explained in a sufficiently detailed and clear
fashion. The limit of a function is first introduced at infinity, and only
afterward at a point; in neither case is a formal definition given. In
general, there are relatively few proofs here. For example, the paragraph
on the “Rules of Differentiation” is structured as follows. First, the
textbook formulates four theorems concerning the derivative of a sum,
the derivative of the product of a function and a number, the derivative
of a product, and the derivative of a quotient, and provides examples.
The authors then write:
First, we will derive the first two rules of differentiation — this is
relatively easy. Then we will examine a number of examples of the
ways in which the rules and formulas for differentiating are used, so
you can get used to them. At the very end of the paragraph, we will
give a proof of the third rule of differentiation — for those who are
interested. (Mordkovich and Smirnova, 2009a, p. 244)
The conditions for the monotonicity of a function are illustrated
using a physical interpretation; the theorem concerning necessary
conditions for the existence of an extremum, usually referred to in
Russian textbooks as Fermat’s theorem, is not proven (nor is it referred
to by the name of its author). In general, the textbook contains
practically no historical information. In this way, it is oriented more
toward practice than theory. Possibly, this accords with the idea of
teaching mathematics on the basic level.
6.4.2
The textbook of G. K. Muravin
and O. V. Muravina
In addressing students in the foreword to this textbook, the authors
emphasize: “To know mathematics means to be able to solve problems.
It is problems that you will have to solve on the Uniform State Exam”
(Muravin and Muravina, 2010b, p. 5). Despite this declaration, the
textbook devotes considerable attention to theory and to working with
concepts and theorems. The concept of continuity is introduced at first
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on an intuitive level: the graph of a continuous function can be drawn
without lifting pencil from paper. Using this visual image of continuity,
the authors next introduce the interval method for solving inequalities.
In 11th grade, the definitions of continuity and the limit are introduced
in the language of “ε–δ.” Quantifiers are used in the formulations
of definitions. Problems that involve computing simple limits are
solved. Theorems on the limits of sums, products, and quotients are
formulated, but not proven; it is pointed out, however, that they “may
be proven, and even without much difficulty” (Muravin and Muravina,
2010b, p. 25). The textbook examines vertical, horizontal, and oblique
asymptotes to the graphs of functions.
In connection with the introduction of derivatives, the concept of
the tangent is raised and discussed first, followed by derivatives and
differentials. The derivatives of elementary functions are introduced
in the same way as they are in Kolmogorov’s textbook: in connection
with geometric considerations, the number e is introduced as the base
of the exponential function e
x
, whose derivative at zero is equal to 1;
then the derivatives of exponential, logarithmic, and power functions
are introduced. In the presentation of integral calculus, the authors first
examine the area of a curvilinear trapezoid, then introduce the integral
as the limit of integral sums, and then demonstrate that the derivative
of a variable area is equal to the function f(x); only after this do they
bring in the concept of the antiderivative.
On the whole, the textbook combines a sufficiently high theoretical
level with clear explanations, a well-phrased presentation, and a
large number of historical discussions. At the same time, it contains
many problems and devotes considerable attention to methods for
solving them.
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