Unformatted text preview: û Note as well that these both agree with the formula for the compositions that we found in the
previous section. We get back out of the function evaluation the number that we originally
plugged into the composition.
So, just what is going on here? In some way we can think of these two functions as undoing what
the other did to a number. In the first case we plugged x = -1 into f ( x ) and then plugged the
result from this function evaluation back into g ( x ) and in some way g ( x ) undid what f ( x )
had done to x = -1 and gave us back the original x that we started with.
Function pairs that exhibit this behavior are called inverse functions. Before formally defining
inverse functions and the notation that we’re going to use for them we need to get a definition out
of the way. © 2007 Paul Dawkins 197 http://tutorial.math.lamar.edu/terms.aspx College Algebra A function is called one-to-one if no two values of x produce the same y. This is a fairly simple
definition of one-to-one but it takes an example of a function that isn’t one-to-one to show just
what it means. Before doing that however...
View Full Document
This note was uploaded on 06/06/2012 for the course ICT 4 taught by Professor Mrvinh during the Spring '12 term at Hanoi University of Technology.
- Spring '12