Glossary
Additive Transformations (Translations)
Changes to a function's graph that involve adding or subtracting constants, resulting in a shift of the graph's position without altering its shape or size.
Example:
Changing to is an additive transformation, moving the entire sine wave up by 2 units.
Combining Transformations
Applying multiple transformations (translations, dilations, reflections) sequentially to a single function to achieve a complex alteration of its graph.
Example:
To model a bouncing ball, you might start with a parabola, then apply a combining transformations to reflect it, stretch it, and shift it to simulate its path.
Dilations
Transformations that stretch or compress a function's graph either vertically or horizontally, changing its size or proportion.
Example:
If a spring's oscillation is , then represents a dilation that doubles the amplitude of its movement.
Domain and Range Changes
Alterations to the set of possible input values (domain) or output values (range) of a function as a result of transformations.
Example:
If has a domain of , then will have its domain and range changes such that its domain becomes .
Horizontal Dilations
Scales a function's graph horizontally by a factor of $|1/b|$ when the input is multiplied by 'b', i.e., $g(x) = f(bx)$.
Example:
If a song's tempo is , then makes the song play twice as fast, demonstrating a horizontal dilation (compression).
Horizontal Shrink
A type of horizontal dilation where the graph becomes narrower, occurring when the input is multiplied by a constant 'b' such that $|b| > 1$.
Example:
If a video's playback speed is , then results in a horizontal shrink, making the video play twice as fast.
Horizontal Stretch
A type of horizontal dilation where the graph becomes wider, occurring when the input is multiplied by a constant 'b' such that $0 < |b| < 1$.
Example:
If a musical note's frequency is , then causes a horizontal stretch, making the note last twice as long.
Horizontal Translations
Shifts a function's graph left or right by adding or subtracting a constant 'h' inside the function, i.e., $g(x) = f(x + h)$, where $h>0$ shifts left and $h<0$ shifts right.
Example:
If a sound wave is described by , delaying its start by 2 seconds, , is a horizontal translation to the right.
Multiplicative Transformations
Changes to a function's graph that involve multiplying by constants, resulting in stretches, compressions, or reflections.
Example:
If models the intensity of a light, then is a multiplicative transformation that halves the intensity.
Order of Transformations
The specific sequence in which multiple transformations must be applied to a function to correctly obtain the transformed graph, typically horizontal changes before vertical changes.
Example:
When transforming to , applying the horizontal shift first, then the vertical stretch/reflection, and finally the vertical shift, follows the correct order of transformations.
Reflection over x-axis
A transformation that flips the graph of a function vertically across the x-axis, occurring when the entire function is multiplied by -1, i.e., $g(x) = -f(x)$.
Example:
If a mountain's profile is , then creates an inverted image, which is a reflection over x-axis.
Reflection over y-axis
A transformation that flips the graph of a function horizontally across the y-axis, occurring when the input variable is multiplied by -1, i.e., $g(x) = f(-x)$.
Example:
If a car's acceleration is , then describes its acceleration if time were reversed, which is a reflection over y-axis.
Reflections
Transformations that flip a function's graph across an axis, changing its orientation.
Example:
If a mountain range's profile is , then creates a mirrored image, which is a reflection across the x-axis.
Transformations of Functions
Processes that alter the graph of a function by shifting, stretching, compressing, or reflecting it without changing its fundamental shape or type.
Example:
If you have the graph of , applying a transformation might turn it into , moving it right and up.
Vertical Dilations
Scales a function's graph vertically by a factor of $|a|$ when the function is multiplied by 'a', i.e., $g(x) = af(x)$.
Example:
If a rubber band's stretch is , then means it stretches three times as much, illustrating a vertical dilation.
Vertical Shrink
A type of vertical dilation where the graph becomes shorter, occurring when the function is multiplied by a constant 'a' such that $0 < |a| < 1$.
Example:
If a signal's strength is , then results in a vertical shrink, reducing the signal's amplitude by half.
Vertical Stretch
A type of vertical dilation where the graph becomes taller, occurring when the function is multiplied by a constant 'a' such that $|a| > 1$.
Example:
If a spring's natural oscillation is , then causes a vertical stretch, making the oscillations twice as high.
Vertical Translations
Shifts a function's graph up or down by adding or subtracting a constant 'k' outside the function, i.e., $g(x) = f(x) + k$.
Example:
If a roller coaster's height is modeled by , adding 50 feet to its design, , represents a vertical translation upward.