TRACT 28.
AND INFINITE SERIES.
115
equation x 3 — 3^/(i 2 —c 2 ) . x = 2b. Now make 2i 'yb — 1, andf 2
— — g 1 •, so shall the above become {^>(1 g) + ^/(1 — g)
_ , 2g’ 2.5.8ff4 „ , - ,
— i — r— ; — - „ „ — &c = the greatest root or the equa-
3.63.6.9.12 ° 1
• 1 c 2 . ♦
tion x 3 — — g 2 ) . x — And when g 2 or is negative,
these become
i'Ai+gs-o + i-gy-D = +
&c z: the greatest root ^jjTthe equation -jrg*)#
— x' that, in general, the infinite series
_ 2g’ 2.5.8^4 _ 2.5 . 8 . 11 . 14.?6
"*■ 3 . 6 — •
&C, is =
* " r " 3.6 3.6.9.12 3.6.9.12. 15 7 18
iV{4 + g•/ ± 1) + il/(l ~ g*S ± 1 ) — the greatest root ofthe equation x 3 — l qr g"-) x — Where the upperand under signs respectively correspond to each other.
123. Again,
... . 7\ , . 1 \ 25 1 2.54’ , 2.5.8.1144
V( + ) y'( t ^ 3/ C 2 X ‘ 3+3 . 6 , 9 c j + 3.6 . 9 . 12 , is c 4
is the least root of the equation x 3 + 3 3 /(c 2 —A 2 ) x — 2b.
this becomes
Then, by taking ~ = l, and-J-
V(i+g)-V(i-g) _ J, 2 Jig* „
2 g 3 + 3.6.9 SC
g:
the least root of the
equation
x 3 + —^r- ] And when g z or c 2
gative, this becomesMi+gV-il-Mi-gy'-OW-i
root of the equation x 3 ■
4S'
is ne-
2.5 g>
3 3.6.9
SVO+g 2 ) r = Z}4g’
+ &c = the least
x = 5T S - So that, in ge-
neral, the infinite series
JL ± 2 ■ 5 g 2 . 2-5-8 -Hg 4 + .
3 3.6.9 "t” 3.6.9. 12.15 —
2.5.8 . 11 . 14.17^63.6.9 .T2TT5 ."TsTsil
&C,
_ V(l+gV'±’)-V(l-5v'±l> .
ls > — 2gV±I- — tile Jeast root °* the
equation, x 3 ±
31/(i=R 2 )
4jt’
X
±1
4g 2 ‘