Excel's functions are just small programs written in a computer language
such as C++. Microsoft does not usually supply the source code for its
software so you'll probably never know "how and why" it works. You could get
some ideas on how things might work such as LOG which computes logarithms
and SIN which computes sines by looking at books on mathematics that show
formulas to do such things. In some cases, the hardware might have a single
instruction to do the function.

Tyro

"SmilingSteve" wrote in message
...
Biff
Thanks for your input. I am not intimately familiar with a lot of excel
formula so I will need time to understand what you suggest. I will get
back
to you.

Is there a good reference for how excel processes its functions? Help
gives
the format and explanations of variables but not the how and why it works.