So O II I A N 1 



H- /3'^ ^ fa o' ([ I ] -V- 2 (r- F') coj a r— (F— F')* wn a F ) 



-4- Z; (i [i] (r— F') -^ (F— Fy C05 a f)1 



^ » . |3^^. (F- #•') fe a' -t- 9 a Z* (F— F') -4- c (F- F')' ] 



Le fjuaiititii /3^; /3^; ^^; ^■^l p'i V' non dipendono (§ 67) 

 che dagli angoli dati ?, ^', ed essendo 



„, •^^^ ^ -•- -^^^ ^' tarnr t cos nr ^ , rr 'efi F' 



tangF'= ; ^Ji , sara ienF== — ; . 



cos / tang ^ cos p' 



Le qnaiitiia poi «, 6, c, si potianno determinare nel- 

 la begueiite uianiera. 



p . . dF' J, d' F' ^ d' F' 



ronciasi A = — — ; B = - — j- ; C= , , , e siccome 



J ,„ . „ sen F' . , d V cos F' 

 dall equazione sen F= — — - si ha -7777= ; t> t 



otterremo 



du ^dF'^^dw ^ ^ 



b^tfl^BcotF' tang V ^ A^ ^''"^P'^ ^^"g ^ 



■<f = ^* ^Cco^F^ang F-^ 3 ^ 5 f^^l^lif^iJ: 



-^A^ ^^ng p'' cot F ' tang F ^^ _^3 ^^^^^ ^^,^ 

 cos F* 



Tx 11, • . ri, sen ■sj -i- sen y tang '(cos 3j . , 

 Dall equazione fangF'=z ; 2 si han- 



'■ coi A iunj' ^ 



