BackElementary Functions and Graph Transformations in College Algebra
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Basic Elementary Functions
Definition and Overview
Elementary functions are fundamental building blocks in algebra. Understanding their properties, graphs, and transformations is essential for analyzing more complex functions.
Identity Function:
Square Function:
Cube Function:
Square Root Function:
Cube Root Function:
Absolute Value Function:
Properties: Domain and Range
Function | Equation | Domain | Range |
|---|---|---|---|
Identity | All real numbers () | All real numbers () | |
Square | All real numbers () | ||
Cube | All real numbers () | All real numbers () | |
Square Root | |||
Cube Root | All real numbers () | All real numbers () | |
Absolute Value | All real numbers () |
Examples: Evaluating Elementary Functions
At :
At :
is not a real number (since square root of a negative is not real)
At :
At :
is not a real number
Transformations of Functions
Definition and Types
A transformation of a function is an operation that changes its graph in a predictable way. The main types are translations (shifts), stretches/shrinks, and reflections.
Vertical Transformations (Shifts)
The graph of is a vertical shift of .
If , the graph shifts upward by units.
If , the graph shifts downward by units.
Example: The graph of is the graph of shifted up 4 units.
Horizontal Transformations (Shifts)
The graph of is a horizontal shift of .
If , the graph shifts left by units.
If , the graph shifts right by units.
Note: The direction of horizontal shifts is opposite to the sign of .
Example: The graph of is the graph of shifted left 4 units.
Examples: Shifts of Square Root Functions
is shifted up 5 units.
is shifted down 4 units.
is shifted left 5 units.
is shifted right 4 units.
Vertical and Horizontal Translations (Shifts): Combined
Functions can be shifted both vertically and horizontally. For example, shifts the graph of right by units and up by units.
Example: If , then is the graph of shifted right 2 units and up 3 units.
Stretches, Shrinks, and Reflections
Vertical Stretches and Shrinks
The graph of is a vertical stretch or shrink of .
If , the graph is stretched vertically by a factor of .
If , the graph is shrunk vertically by a factor of .
Example: is a vertical stretch of by a factor of 2. is a vertical shrink by a factor of 0.5.
Reflections
reflects the graph of across the x-axis.
reflects the graph of across the y-axis.
Example: is the reflection of across the x-axis.
Summary Table: Effects of Transformations
Transformation | Equation | Effect |
|---|---|---|
Vertical Shift | Up units if , down units if | |
Horizontal Shift | Left units if , right units if | |
Vertical Stretch | , | Stretches graph vertically by |
Vertical Shrink | , | Shrinks graph vertically by |
Reflection (x-axis) | Reflects graph across x-axis | |
Reflection (y-axis) | Reflects graph across y-axis |
Combining Transformations
Multiple transformations can be applied to a function in sequence. The order of operations can affect the final graph.
Example: is the graph of reflected across the x-axis, shifted right 3 units, and up 1 unit.
Example: is the graph of reflected across the x-axis and shifted left 2 units.
Application: Graphing and Analysis
To analyze a transformed function, identify the sequence of shifts, stretches/shrinks, and reflections.
Graphing multiple related functions on the same axes helps visualize the effects of each transformation.
Additional info:
Understanding these transformations is foundational for graphing polynomial, rational, exponential, and logarithmic functions in College Algebra.
Practice by applying transformations to basic functions and predicting the resulting graphs.