May I ask a very simple but fundamental question about Calulators - specifically the Casio fx-CG20 (which I have just purchased)?

If I use one of the transcendental functions (ln, cos etc), is the solution provided by an algorithm built into the processor chip circuits, or is there a firmware layer that takes care of such calculations?

I would be grateful for anyone who can shed light on this for me.

Many thanks.

Welcome to Cemetech, Rodney. Like almost all graphing calculators, the Casio fx-CG20 ("Casio Prizm") is essentially a computer. That means that it has a general-purpose processor, RAM/Flash to hold data and an operating system, and can run arbitrary code. Its operating system includes all of the math tools that you use, including the underlying math functions like sin(), cos(), and tan(). Many modern general-purpose processor architectures like x86 and ARM do contain a huge number of built-in math functions, especially if they have FPUs (Floating Point Units) built-in. The SH4A CPU in the Prizm does not have an FPU, so transcendental functions are computed in software by the OS. Hope this helps.

Thank you very much for your reply. Perhaps I may ask a supplementary question?

The reason for my inquiry was that I am interested in how the functions are calculated. I know that in the past, when ALU's typically had limited functionality, CORDIC methods were often used as these could be efficiently implemented with simple adders. However, if the OS is calculating the Trig functions, is it more likely that it is using a Series expansion od some kind? Do you happen to know?

Best regards