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Inverse Function


Date: 9/15/96 at 13:54:54
From: Anonymous
Subject: Inverse Function

Given f(x)= 1 - 2/x    then  f-1(x) is: 

I tried reversing the equation, switching the x and y and solving 
for x, but the answer I got didn't match any of the choices I had. 

Dianne


Date: 9/19/96 at 16:41:3
From: Doctor Robert
Subject: Re: Inverse Function

y = 1 - 2/x 

Switching the x and the y's in order to find the inverse we have
        x = 1-2/y
      x-1 = -2/y
 (x-1)/-2 = 1/y
        y = -2/(x-1) so that in inverse function f^-1(x) = -2/(x-1)

Check a few points!  
 (2,0) is a point of f(x)  and (0,2) is a point of f^-1(x).  

I think we've got the right answer.

-Doctor Robert,  The Math Forum
 Check out our web site!  http://mathforum.org/dr.math/   
    
Associated Topics:
High School Equations, Graphs, Translations

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