2Sf REV. T, P. KIKKMAi» OK MNEMONIC AIDS 



(«i^ le is an abbreviation of less, or — 



seff. op. in (A) means tke segment of e opposite, noC 

 adjacent to, 5, whose square is the subject of the 

 proposition. Pronounce two long, to avoid confu- 

 sion of it with to. Bang is the angle opposite to 6. 

 By putting in A for s its value IfT a cos B. we obtain 

 ¥ — a^-\-c^ — cos B. 2ac. (B.) 



(4), The following: two groups of mnemonics give the solu- 

 tions of ail plane and spherical triangles. SubyD is a dis- 

 syllable; sleb' ajid slec are syllables ;. s. sla is a dissyllable, as 

 is b'c also. 



Side to Sin op. as Side to Sin op. (a.) 



SubyD Sines or sides is taf Sum by taf Diff. (6.) 



T^quaf 'A is sleb slec by s. sla, (c.) 



the num, i&b'cof sisquaf 'A; (d.)- 



In sphere put sines of facs. (e.) 



le cotasquaf in p6. has co's 'bove and low. (/I) 



side 'c is coy. sum (ab) {ff.) 



where Siy is chaCang two mean kb by S (ab.) 

 In these two lines ab is a syllable. 

 These are abbreviations explained thus :^- 

 (a.) Side b is to the sine of its opposite angle, as side c to 



the sine of its opposite angle, as side a, &c. 

 (5.) SubyD means Sum by Difference; to/" stands for ten- 

 gent of hal/I 



sine A -|- sine B a -\- b tan. ^ ( A -j- B) ^ (5.) 



sine A — sine B a — b tan. -^ (A — B) ' 



sines or sides means sines of angles, or' sides opposite 



those angles. 

 (jS.y Tasquaf is tan squared of haif: there is no risk of error 



here in pronouncing A and a alike ; 

 sfeb is (s -— i), * being semiperimeter; vide Ik (3) ffi- 



tan.HA- ^^-/>^^7"> (c.) 



■* s (s <0J 



X^y The wwrnerator on the right (c) is be X 8^-^ i A 

 = (* — &)(« — c) id.) 



