Lesson Do not fall into a TRAP when analyzing problems on trigonometric functions

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Do not fall into a TRAP when analyzing problems on trigonometric functions


Problem 1

Describe what the graph of   f(x) = -sin%283x-pi%29-2   would look like?
Address all numerical elements and their effects on the parent function.

Solution

Given function  f(x) = -sin%283x-pi%29-2  is IDENTICAL to / (is the same as)

                f(x) = sin%283x%29+-2.


The parent function is  a(x) = sin(x).


Amplitude of f(x) is 1.


Period of f(x) is 2pi%2F3.


Phase shift of f(x) is  0  (zero).


Vertical shift is  -2  (2 units down).

----------------

This problem is a  TRAP :   it has a huge underwater stone for unexperienced reader.

The sign  "-"  (minus)  before sine and the shift by  pi  in the argument
mutually annihilate each other,  so the final function,  actually,  has no shift (!)

The meaning of the problem is to teach a reader recognizing
such traps to avoid falling into them in the future.


My other lessons in this site on plotting and analyzing functions are
    - Finding x-intercepts and y-intercepts
    - Compressing and stretching graphs
    - HOW TO PLOT transformed functions
    - HOW TO write functions for transformed plots
    - HOW TO PLOT transformed periodic trigonometry functions
    - Analyzing periodic trigonometric functions for the amplitude, the period, vertical and horizontal shifts
    - The domain and the range of transformed functions
    - Write a function which is a result of given transformations of the parent function
    - Describe transformations from the given parent function to final function
    - Writing a function rule for a function based on its wording description
    - Constructing a function based on its given properties
    - Finding inverse functions
    - Miscellaneous problems on plots of functions
    - Given a point on a plot of a function, find the corresponding point on the plot of transformed function
    - Special advanced problems on finding the domain of functions
    - Special advanced problems on finding the range of functions
    - OVERVIEW of lessons on plotting and analyzing functions

Use this file/link  ALGEBRA-I - YOUR ONLINE TEXTBOOK  to navigate over all topics and lessons of the online textbook  ALGEBRA-I.

Use this file/link  ALGEBRA-II - YOUR ONLINE TEXTBOOK  to navigate over all topics and lessons of the online textbook  ALGEBRA-II.


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