Which of the following represents the domain of the function  `f(x)=ln(1-x)`?

1. `[1,oo)`
2. `(1, oo)`
3. `(–oo, 1]`
4. `(–oo, 1)`

What is the domain of the function  `f(x) = ln(4-x)`?

1. `x < 4`
2. `x <= 4`
3. `x > 4`
4. `x >= 4`