n- [ I — cof (:'. — 4-^)] — I ~ cof (1>, h. e. 

 n fin l (.'. — <^) — fin h ^, undc fequitur 



j ^ n fin ^ y. 



tang ?, Cp =r = 



n coi k ci.±i 



Habemus ilaquc 



tang l A O E = --. ~- , 



n cof I a -f- I 



T t ^-w T-. ?? fin i a 



Defmiuntur igitur anguli ^ A O E, ^ A O F, ^ E F^eodcni 

 modo per ^ a, ac in 1. pioblemate AOE, AOF, EOF, 



per 7. (§. 4.}. 



§. iS. Ad folidi naturani cognofccndani, aequatio- 

 ncm inter ternas coordinatas OL=:a:, LK. ~j', K C :: z, 

 qLiacicre praeftat. Eft nempe cofAOC~^, cofBOC 

 — Jli!, eL O M := xcof a-f-jfin a (§. S.), unde ob 



n- cof B O C n: n- — I -h cof A O C ($. 17.), 

 oril(n- ;r (x cof a -\- y fin a) — [if — i) O C -r X, 



vel ob OC=:]/(x'-H-/-h2,^), 



1. o ~jV X* [>i* fin* a — 2 (i — cof r'.)] 



-}-/ [n" cof a — 2 /1' H- i) -h z' («' — 2 n -|- 1) 

 — 2 n' xy fin a (n^ cofa — i). 

 iVora A^a y^(ari. 7jnp. Scic?i/. Tom. XIL D d Af- 



