What is the inverse of y= e^(x-1)-1 ?

1 Answer
Dec 7, 2015

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

Explanation:

To compute the inverse, you need to follow the following steps:

1) swap y and x in your equation:

x = e^(y-1) - 1

2) solve the equation for y:

... add 1 on both sides of the equation...

x + 1 = e^(y-1)

... remember that ln x is the inverse function for e^x which means that both ln(e^x) = x and e^(ln x) = x hold.
This means that you can apply ln() on both sides of the equation to "get rid" of the exponential function:

ln(x+1) = ln(e^(y-1))

ln(x+1) = y-1

... add 1 on both sides of the equation again...

ln(x+1) + 1 = y

3) Now, just replace y with f^(-1)(x) and you have the result!

So, for

f(x) = e^(x-1) - 1,

the inverse function is

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

Hope that this helped!