ao5 MEDITATIOKES DE QJ^AmiTATlBVS 



nonnulhs eiusmodi Formuhs fpcciales , vt , praccini cal- 

 culi ditficiilr.ue atque prolixitatc , hinc cxccrpi pofluit, 

 Harum aut.m veritas , atftu multiplicando , tkile cxplo- 

 rari potent. . 



(4_i^y-3)(_l-i_y-3)c^+4- (-iqpy-3)*(-i:f:;^-3)=-4-+-4V-3. 



(_iqiy3)'-+8-a',(-iTV-3)=^.(-i±"^^-3M-T^V-3)'=-8-(-a)*. 

 (,_f-2y_i)(i_2y_x)--H5-, (i-2V-i)'H-3(:iV-i-i-i)--haV-i- 



(i-ay-i)'=-ii+ay-ii(-j±v-i)'r;4-2di-"^'' ii«\i-iV-0'— -^^^^^+^^*^ 



(.iZpy3)'-.ioT<sy3-,(-io-|-6y3)''.(-io-6y3"^';=(-i-i-V3)(-i-V3)=8'': 



(_io4-6y3)'''.(-JO-6V3)'-'=-5-(-io+<5>'3)'-'=-a.(-i-i-V3)=-H2-2y3. 

 (-10-6^3)-;'. (-10-4-6^3)'^ '=-2. (-10-6^3)'^ '--2.(-i-V3)rz-4-2-4-2> 



(r4:;V-3/rz3TvV--3-,(3-4--V-3)'''.(3-";V--3)--'=('.^-jV-3XJ-iV-3). 



(_i4.y_i)^-_iy-i;(i+y-j)'-+2V-i-(-i-Vi)=4-2V-ii(x-V-x)*=:-a 



His pracmidis , quae ad refolutioncm aequationis cubicae 

 pertincnt , nunc agamus dc conrtrudione radicum einsmo- 

 di aequationis , ctji c.isdem tantum nou femper quantita- 

 tes imag.nariac ingrcdiantur, 



$. 38. Sint quatuor reia.ingula a, p, y, 5", 

 '«•lo-ad idem punctuin V coniugata , ct pro h-^(\hw!> paralle- 

 lepipedorum pollibilium ad P coniug.itorum aflfumta , 

 litquc practcrca P T altitudo pofitiua ( furfum tcndens ) 

 — _|- i- ^ ct P ^ altitudo priiiatiua ( dcorfum tcndcns ) 

 zii — c : orientur oifto paraUelepipeda diucrdi ad P con- 

 iugata , ct quidcm quatuor capaciiatis porituuc ->t-alfc^ 

 rcliqua quatuor autcm capacitatis priuatiuae — a b c. Ni- 

 mirum crit paralickpipcduoi pnjitiuum 



« ) 



