Section 2.4 Topics:
    Operations with functions;
        Basic operations with functions;
        Composition of functions;
        Applications;
        Examples. 

Section 2.5 Topics:
    Inverse functions;
        One-to-one and invertible functions;
        Determining whether a functions is one-to-one;
        Inverse functions using function notation;
        Graphs of  f and f^(-1);
        Finding inverse functions mentally;
        Examples.