Did you know that every equation in Calc Zone Pro has a published source?  Not only do you see all of the math associated with your analysis, you can also find the source for the equation.  To find the source, open any formula and click on the Formula Help button in the upper right corner of the ribbon (across the top).

You will never have to worry about using an equation that you know nothing about.  The help file is also filled with various charts for things like friction and rolling resistance to give you a starting point for your calculations.  All of this is included at no additional cost to you.

The formula help file is just like the program; it is constantly evolving and growing.