Functions_2 program discusses functions in more depth. It includes relations and their graphs, discuss a function from different aspects including how to determine a graph is a functional graph or not. What is ordered pairs. How ordered pairs define a relation is a function or not? It discusses parabola and its characteristics (vertex, axis of symmetry, minimum and maximum value) and how to sketch it quickly. It discusses other types of functions like constant, linear, polynomial, absolute value, square root, several expressions functions. Combined and composite functions. It includes every thing you want to know about inverse of a function and how to test for it. It includes over 190 solved exercises step-by-step in a simplified manner. It is suitable for SAT, GCE and international tests.