Tuesday, December 16, 2014

Transformations of Functions




All types of functions have a parent function, the simplest type of function in a family of functions. Some common ones are:  , ,
Functions can be manipulated by a vertical shift, horizontal shift, vertical stretch, horizontal shrink, or a reflection 

Horizontal and Vertical shifts: depending on where x is manipulated will cause a horizontal or vertical shift. If the x is added or subtracted outside of the parenthesizes, then the graph will shift up or down. If the x is added or subtracted inside of the parenthesizes, then the graph will shift left or right.

Vertical shift up: 
Vertical shift down:  
Horizontal shift to the right: 

Horizontal shift to the left

Vertical Stretch and Horizontal Shrink: a horizontal shrink and a vertical stretch affect the width of a function. In a vertical stretch or shrink, the function is multiplied by c outside of the parenthesizes. If c<1, then it will be a vertical shrink. If c>1, then it will be a vertical stretch. In a horizontal stretch or shrink, the function is multiplied by c inside of the parenthesizes. If c>1, then it will be a horizontal shrink. If c<1, then it will be a horizontal stretch.

Vertical stretch: 

Horizontal shrink: 

There are ways to tell if the graph has been affected vertically or horizontally. In a vertical stretch or shrink, there is no change in the x-intercepts. In a horizontal stretch of shrink, there is no change in the relative minimums or maximums or y-intercepts.

Reflections: a reflection mirrors the function over either the x-axis or y-axis. When –c is multiplied outside of the parenthesizes, the function reflects over the x-axis. When –c is multiplied inside of the parenthesizes, the function reflects over the y-axis.

Reflection over x-axis: 


Reflection over y-axis: 


Reflections also bring to light the idea of even and odd functions. If f(-x) = f(x), then the function is even. If f(-x)= -f(x), then the function is odd.  However, if f(-x) does not equal either, then the function neither odd nor even.

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