If f is any function from A into B, we can describe the inverse image as a function from B into P(A), which is also commonly denoted . If b B, (b) = {a A | f(a) = b}. If does have an inverse, the inverse image of b is {1(b)}. a. Let g: RR be defined by g(x) = x. What are g(4), g(0) and g(-1)? b. If r: R Z, where r(x) = [x], what is r(1)?