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I need to find the inverse of this problem 

f(x)=3^x-1

 

After doing my maths, I got an answer of

f^-1(x)=log3(x)+1

 

Thank you so much to whoever assists me with this topic

 Jan 16, 2019
 #1
avatar+128053 
+1

Let's write

 

y = 3^(x - 1)       take the log of both sides

 

log y = log 3^(x - 1)

 

log y = (x - 1)log 3

 

log y / log 3 = x - 1

 

 [ log y / log 3 ] + 1   = x            swap x and y

 

[ log x / log 3 ]   + 1   = y   =   the inverse

 

 

cool cool cool

 Jan 16, 2019

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