cragar, sorry for the rather silly answers you have got. No, calculator (and computers) do NOT typically use MacLaurin seiries for trig functions, exponentials, etc. I thought they did for a long time, then ran across a website that talked about a general class of numerical algorighms that are used for that. I had bookmarked the site but that was years (and a couple of computers ago) and I can't find it now. I will continue looking.