IV. Special Graphs

B. Greatest Integer Function

The greatest integer function (also called a step function) is actually a piecewise defined function with a special definition. The function has the notation f(x)=||x|| or f(x)=[[x]] when it is written, but the TI-86 designates this function by using f(x)=int(x) and is found in the MATH NUM menu. This function is the greatest integer less than or equal to x. So, f(1)=1 and f(1.4)=1. Since this is a piecewise function you should use DOT mode.

Example: Graph the function f(x)=||x|| (the greatest integer function). Make sure that you use DOT mode.

Access int using .	Enter the function. and put in DOT.
Graph with ZDECM.	Without DOT (not good).