Conner B. answered 03/04/20
Chemical Engineer
The innermost operation is f(5). At x = 5, f(x = 5) = 1, as given. So then you have f-1(1) when you replace f(5) with 1. The notation f-1(y) essentially asks for the x at which f(x) = y. For some functions this can be problematic (e.g. periodic functions). The problem states that the function is one-to-one, so when you do f-1(1) the only point available is 5.