Hinc fimul apparet fubftitutio, qua formula propofita faci- 

 lius redditur integrabilis^ ponendo fcilicet z- 1 ^-^- 3 ; ve- 

 rum non nili cafu quodam in eam inciejere licuiffet. 



§. 4. Evoluto integrali formulae propofitae occafio- 

 nem arripui tentandi integrationem formularum 



d% , oZ 



et 



(3+Z2;)/(i+3zz) (3 — zz)Y (1 — 3 z z) 

 et cum rem fuccedere pro prima obfervaffem, operae pre- 

 tium effe exiftimavi integrale illius ope allatae iubftitutio- 

 nis evolvere. Pro integranda igitur formula 



dz 



3 

 (3 + zz)/(i+3Zz) 



3 . . 



concinnitatis gratia pofito y (1 ■+- 3 z z) — 2. x, habebitur 



nz 8t3 - J , hinc 3 +zz = 8I + ic3i ac 3z-i^ii, 

 fubftitutis his valoribns obtinebitur 



d % I x d x Y 3 



(3+ zz)l >( I + 3 , 2) (i+X ! )K(S* 3 -x) 

 Ponatur iam vt ante 



t = ^'-3r-t jyy), c et 



3 



I+ ^-3(i-r +rr) ^ 



»ec 



