The domain of the function

$$f(x) = \sqrt {(2 - x)(x - 3)} $$ is

If $$f(x) = {{x - 2} \over {x + 2}}$$, x $$\ne$$ $$-$$2, then what is f^$$-$$1(x) equal to ?

If f(x) = log₁₀ (1 + x), then what is 4f(4) + 5f(1) $$-$$ log₁₀ 2 equal to ?

Let z = [y] and y = [x] - x, where [.] is the greatest integer function. If x is not an integer but positive, then what is the value of z?