3. The function f is a set of ordered pairs, (x,y), then the changes produced by f can be “undone” by reversing components of all the ordered pairs. The resulting relation (y,x), may or may not be a function. Inverse functions have a special “undoing” relationship.
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5. Relations, Functions & 1:1 1:1 Functions are a subset of Functions. They are special functions where for every x, there is one y, and for every y, there is one x. Relations Reminder: The definition of function is, for every x there is only one y. Functions 1:1 Functions Inverse Functions are 1:1
6. 1100 1400 1000 1300 900 1200 f(x) x 1400 1100 1300 1000 1200 900 g(x) x
21. There is a relationship between the graph of a one-to-one function, f, and its inverse f -1 . Because inverse functions have ordered pairs with the coordinates interchanged, if the point (a,b) is on the graph of f then the point (b,a) is on the graph of f -1 . The points (a,b) and (b,a) are symmetric with respect to the line y=x. Thus graph of f -1 is a reflection of the graph of f about the line y=x.
23. Example If this function has an inverse function, then graph it’s inverse on the same graph.
24. Example If this function has an inverse function, then graph it’s inverse on the same graph.
25. Example If this function has an inverse function, then graph it’s inverse on the same graph.
26. Applications of Inverse Functions The function given by f (x)=5/9x+32 converts x degrees Celsius to an equivalent temperature in degrees Fahrenheit. a. Is f a one-to-one function? Why or why not? b. Find a formula for f -1 and interpret what it calculates. F=f (x)=5/9x+32 is 1 to 1 because it is a linear function. The Celsius formula converts x degrees Fahrenheit into Celsius. Replace the f(x) with y Solve for y, subtract 32 Multiply by 9/5 on both sides
