SOLUTION: What is the inverse function of f(x)= 3^(x-1) -2 I thought I would get x= 3^y-1 -2 then x+2 =3^y-1 then logs but I am confused

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: What is the inverse function of f(x)= 3^(x-1) -2 I thought I would get x= 3^y-1 -2 then x+2 =3^y-1 then logs but I am confused      Log On


   



Question 634750: What is the inverse function of
f(x)= 3^(x-1) -2

I thought I would get
x= 3^y-1 -2
then x+2 =3^y-1
then logs but I am confused

Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
What is the inverse function of
f(x)= 3^(x-1) -2
y= 3^(x-1) -2
to find the inverse, interchange x and y, then solve for y
..
x=3^(y-1)-2
x+2=3^(y-1)
take log of both sides
log(x+2)=(y-1)log3=ylog3-log3
log(x+2)+log3=ylog3
Inverse,y^-1=(log(x+2)+log3)/log3