Question

How do you find the inverse of `f(x)=log(x+7)`?

Answer 1

Since `ln` or `log_e` isn't used, I'll assume you are using `log_10` but will provide a `ln` solution too.

For `log_10(x+7)`:
`y=log(x+7)`
`10^y=x+7`
`10^y-7=x`
`f^-1(x)=10^x-7`

For `ln(x+7)`:
`y=ln(x+7)`
`e^y=x+7`
`e^y-7=x`
`f^-1(x)=e^x-7`