### Saving The Appearances

Yesterday we loaded programs AANGLE and SANGLE, used in computing annuities. For the record, one has $a_{n\rceil r} := {{1-(1+r)^{-n}}\over r}$ and $s_{n\rceil r} := {{(1+r)^n -1}\over r} (= (r+1)^n a_{n\rceil r})$. I’ve gotta go mark papers; if the actual rant on this material ever materializes, it won’t be till tomorrow at the soonest.