EIVSQVE VARUTIONE. 127 



vt obtineamus has fbrmas : 



i°. v*d<p*-jz + 2^?d£ tt2\dv^vvd^— 1J ~^ 



-\~2ccQd? 

 quae fado v~cx fiunt 



i°. x i d(p 2 --\-2?d? et a 9 . dx z -\- xx £§*—*-—£ 



-t- : *Q^ 

 eritque : 



rfP==7 M*V(J>fin.'»» (*</<£= =7 (M^(J)fuutf-N<&) 

 exiftente 



M = ^cof.>i^^(i--5cof^)--^(3co(:^7co{:v5 



N=^r(i-3cof>i : )+7?r(3cof.^-5cof.Y;- c ^;(3-3ocof^ 



-t-S^cof.^), 



X. Ex priore aequatione iam eft </<P=^~ 

 qui valor in altera fubftitutus dat : 



vnde elicitur : 



rf*=</<V(aQH--^-iS) vel etiam 



^^^VCaQ+^-jl) 



hincque difcimus quantitatem ^Q-f-^ — ^nun- 

 quam fieri poffe negatiuam j euanefcere autem pot- 

 eft , quod fit dum Luna vel in apogeo verfatur 

 vel in perigeo, quandoquidem vtroque eafu fit dxzo. 

 Ceterum fi vires perturban tes abeffent pro motu 



medio, 



