SI2 
& ) ° ( <& 
autem hæc & fimilia, fine adminiculo expresfionum 
imaginariarum perfici queant, in fequentibus bre- 
viter exponere animus eft. 
PROP. i. 
Sit radius AB — i (Tab. XL Fig. i.), arcus 
BC — v , arcus ÛC — x, & erit Sin. v. Cob x 
Sin. v + x ^ Sin. v — x 
2 2 
Sumatur enim in quadrante MCB arcus CE = 
DC, & ducatur chorda DE occurrens radio AC in /. 
Demittantur deinde a pun&is D , 1, C , E normales 
DF , IG, CH, & EK in radium AB. Ob fimilia 
triangula A1G & AHC, erit AC : CH : : AJ : IG, 
u a. «v nr rn DF-\~EK Sin. i' + x 
hoc eft Sin. v. Col. x = IG = = — * 
2 2 
Sin. v — x 
Sin. 2 v 
Coroll. Si v = x, erit Sin. v Cof. v = 
PROP. 2. 
Stantibus iisdem ac in Prop, i, erit Cof r. Cof. x 
Cof. v 4- x Cof. v — x 
2 2 
Ob fimilia triangula AGI, AHC \ erit AC: AH:: AJ: AG , 
tu ^ _ ^ . AF AK Cof. r-f-x 
hoc eft Cof v. Cofx = = — — — — = - 
2 2 
Cof. v — x 
■+ — ~ — “• n 
2 Cor. i. 
