# I Inverse of a function

1. Jun 17, 2016

### Eishan M

Hi,
What is the inverse of f(x)= e^x + e^-x +1?

2. Jun 17, 2016

### Eishan M

This question has been intimidating me for quite a while. I'm unable to reach a definite conclusion to this. Please help

3. Jun 17, 2016

### Hawkeye18

Try solving $$e^x+e^{-x}+1=y.$$

4. Jun 17, 2016

### mathman

Convert problem into a quadratic equation by $u=e^x,\ u^2+1+u(1-y)=0$. Get u as a function of y, then x=ln(u).