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how do I find the inverse of, f(x)=2+ex+4

 May 19, 2016
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Let f(x)  = y   and we have

 

y = 2 + ex+4      the idea is to get x by itself and then "switch" x and y

 

Subtract 2 from both sides

 

y - 2   =  ex + 4     take the natural log of both sides

 

ln [y - 2] = ln e x + 4       and by a log property we can write

 

ln [y -2] = (x + 4) ln e          ln e  = 1    so we can now ignore this

 

ln [y - 2]  = x + 4           subtract 4 from both sides

 

ln [y - 2]  -  4   = x         "switch" x and y

 

ln [x - 2] - 4  = y         and, for y, write  f-1(x)     where f-1(x)  indicates the inverse function

 

ln [ x - 2 ] - 4  = f--1(x)

 

Here's the graph of the original function and its inverse : https://www.desmos.com/calculator/wr4hgezjxu

 

 

cool cool cool

 May 19, 2016

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