) 204 ( |p?<- 

 gulos inclinatorios definientes, fequentem induent formam: 



I. ^ = cof. a H- cof. p -h cof y. 



II. -^ =: fin. « 4- fin. p -{- fin. y. 



III. o — tang. a — 2 tang. p -+- tang. y. 

 Hinc fi fuerit altitudo MDzznzzo, erit 



II. o - fin. «-4- fin. j3-f- fin. y, 



cui aeqilationi, pariter ac tertiae, fatisfit fumendo p r o et 

 Y - — a ; ex prima autem defiiiitur angulus a , cum fit 

 cof a = ^J^". 



la 



Problema III. 



Tab. V. §• 13. '5'/ compages ex quotcunque trabibus confc" 



Fig. 8. ta in pun&is fixis AetE infijlat, iun^urae autem B, C, D, 



ctc. grauentur ponderibus P, Q, R, etc. inuenire ftatum 



aequilibrii , in quem haec compages fe componet , dein vireSy 



quas in anterides in A et E exerit , ac tertio vires , quas 



Jingula trabes fujtinere debet, 



Solutio. 



Sit longitudo trabis AB:r^, BCr^, CDrrr, 

 ctc. dudisque redis horizonti parallelis B ^, C f, D </, etc. 

 Yocentur inclinationes ad horizontem 



BAfl = a; CB^:r(3i DC<: = -Yi ED</ = -5i etc. 



cruntque hinc interualla 



Aa-a cof. a j B^ r: ^ cof (3 i C<: = f cof. y j D//= </ cof. 5 i etc. 



et 



