The graphs of the elementary functions

The graphs of algebraic functions
The graphs of the polynomial functions
The source or original polynomial function
Translating (parallel shifting) of the polynomial function
Coordinates of translations and their role in the polynomial expression
The source and translated cubic function
The transition of the cubic function expression from the general to the translated form
Elementary functions are,   Algebraic functions and Transcendental functions
Algebraic functions
· The polynomial function   f (x) =  yanxn + an-1xn-1 + an-2xn-2 + . . . + a2x2 + a1x + a0
y a1x + a0                                                   - Linear function
y = a2x2 + a1x + a0                                                      - Quadratic function
y = a3x3 + a2x2 + a1x + a0                                       - Cubic function
y = a4x4 + a3x3 + a2x2 + a1x + a0                        - Quartic function
y = a5x5 + a4x4 + a3x3 + a2x2 + a1x + a0         - Quintic function
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 · Rational functions - a ratio of two polynomials - Reciprocal function - Translation of the reciprocal function,     called linear rational function.
The graphs of the polynomial functions
The graph of a function is drawing on the Cartesian plane, plotted with respect to coordinate axes, that shows functional relationship between variables. The points (x, f (x)) lying on the curve satisfy this relation.
The source or original polynomial function
Any polynomial f (x) of degree n > 1 in the general form, consisting of n + 1 terms, shown graphically, represents translation of its source (original) function in the direction of the coordinate axes.
The source polynomial function
 fs(x) = anxn + an-2xn-2 + . . . + a2x2 + a1x
has n - 1 terms lacking second and the constant term, since its coefficients, an-1 = 0 and a0 = 0 while the leading coefficient an, remains unchanged.
Therefore, the source polynomial function passes through the origin.
A coefficient ai of the source function is expressed by the coefficients of the general form.
Translating (parallel shifting) of the polynomial function
Thus, to obtain the graph of a given polynomial function  f (x) we translate (parallel shift) the graph of its source function in the direction of the x-axis by x0 and in the direction of the y-axis by y0.
Inversely, to put a given graph of the polynomial function beck to the origin, we translate it in the opposite direction, by taking the values of the coordinates of translations with opposite sign.
Coordinates of translations and their role in the polynomial expression
The coordinates of translations we calculate using the formulas,
Hence, by plugging the coordinates of translations into the source polynomial function  fs(x), i.e.,
 y - y0 = an(x - x0)n + an-2(x - x0)n-2 + . . .  + a2(x - x0)2 + a1(x - x0)
and by expanding above expression we get the polynomial function in the general form
f (x) =  yanxn + an-1xn-1 + an-2xn-2 + . . . + a2x2 + a1x + a0.
Inversely, by plugging the coordinates of translations into the given polynomial f (x) expressed in the general form, i.e.,
 y + y0 = an(x + x0)n + an-1(x + x0)n-1 + . . .  + a1(x + x0) + a0
and after expanding and reducing above expression we get its source polynomial function.
Note that in the above expression the signs of the coordinates of translations are already changed.
Cubic function    y = a3x3 + a2x2 + a1x + a0
The transition of the cubic function expression from the general to the translated form
Applying the same method we can examine the third degree polynomial called cubic function.
1)  Calculate the coordinates of translations
 substitute n = 3 in and
2)  To get the source cubic function we should plug the coordinates of translations (with changed signs) into the general form of the cubic, i.e.,
y + y0 = a3(x + x0)3 + a2(x + x0)2 + a1(x + x0) + a0,
after expanding and reducing obtained is
 the source cubic function.
3)  Inversely, by plugging the coordinates of translations into the source cubic
y - y0 = a3(x - x0)3 + a1(x - x0),
after expanding and reducing we obtain  y = a3x3 + a2x2 + a1x + a0  the cubic function in the general form.
 Thus,         y = a3x3 + a2x2 + a1x + a0     or      y - y0 = a3(x - x0)3 + a1(x - x0), by setting  x0 = 0  and  y0 = 0 we get the source cubic function  y = a3x3 + a1x  where  a1= tanat .
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