J» 
_ SS ) o ( _ ary 
rit vel s = i , (i — i^) 1 — a<j 2 — r 4 2, azzz c — i, 
vel $ =. — i, a = 1 — c. 
, 5. VI. 
Dadem methodus ad formam x 4 -4- Ær* 4-2?x* 
-+- Cx-î- D — 0 adplicari poteft; fi enirn in hac ponatur 
x = y _)_ E, fimili ratione invenietur aquatio pro £ tertii 
gradus, uc a , b , c determinentur ad fupputandam for¬ 
mam y*-±.aly 3 -±-cb 2 y 2 -bab’y-bl> 4 — 0. De aequatione 
vero pro E notandum 1:0 dato A 2 D — C 2 , unam ra¬ 
dicum elfe nihilo aequalem, reliquasque duas ex aequa¬ 
tione quadratica dependere; 2:0 pofito A'— 4AB-+- 
8 C — o, erit 4E -b A= o,a ~o, cb 2 =B — fd 2 , b =s 
(tv« — ! dC - 4 - -Ö) 4 . 3:0 Si ambae conditiones ob¬ 
tineant, aequatio propofita ad quadraticam deprimi pot¬ 
eft: fit namque A 2 D r=C 2 , five x 4 -+-Ax~> 4- Z?x 2 4- 
C z i_ 
Cx -4- — = 0, & afiumatur (x 2 4 £x 4 D“) (x 2 4- 
Fx 4- D 2 ) — 0 = x 4 4 £x 3 4- Z) T x 2 4- D 2 Fx \D—o 
4 - Fx 3 4 —EFx 2 4 D 1 Ex 
4- D^x* 
erit A~ E 4 F, B—2D 2 4 EF~ 2D 2 4 AE — E 1 1 
E — B 4 2 D 2 , & F—A — E— \A 4 
^kA 2 — B 4 2D 2 , fi ercro \A Z — B 4 2 D~ = 0 » 
C 
adeoquei^ 1 — B 4 2~j=o, five x? 3 — 4^/? 4 8^ 
2=0, erit E=F , indeque x 4 4 ^a- 3 -+-Bx 2 4 Cx 4 
C 2 C ' 
—— — (at 2 4 \Ax 4 — t 
A 2 ' A 
C\ 2 
{x+iA—v\'gA 2 -~~j = 0. Obfervandum autem hic 
) =(x4é/î4 1 /^A 2 —-) 
