Leonhard Euler · 1748 · Internet Archive
Introductio in analysin infinitorum
All 320 leaves · leaf 319
Transcription
IN RADICIBUS ÆQUATION. INDAGAND. 289
sius $p$ valorem indicabit. Erit autem iste radicis valor $= p + \frac{(n+2)A+B}{\frac{1}{2}(n+1)(n+2)A+(n+1)B+Cp}$.
CAP. XVII.
Quod si autem $p$ non fuerit radix maxima, tum inventio maxime multo magis adhuc impedietur; unde sequitur æquationes, quæ contineant radices æquales, hac methodo per Series recurrentes multo difficilius resolvi, quam si omnes radices essent inter se inæquales.
348. Videamus nunc quomodo Series recurrens in infinitum continuata debeat esse comparata, quando denominator fractionis habet Factores imaginarios. Sint igitur fractionis
$\frac{a+bz+cz^2+dz^3+\&c.}{1-\alpha z - \beta z^2 - \gamma z^3 - \delta z^4 - \&c.}$
Factores denominatoris reales $1-qz$, $1-rz$, \&c., insuperque Factor trinomialis $1-2pz \cos\phi + p^2z^2$ continens duos Factores simplices imaginarios. Quod si ergo Series recurrens ex illa fractione orta fuerit
$A+Bz+Cz^2+Dz^3+ \dots + Pz^n + Qz^{n+1}$,
erit, per ea quæ supra exposuimus, coëfficiens $P = \frac{A \cdot \sin((n+1)\phi) + B \cdot \sin(n\phi)}{\sin\phi} p^n + Cq^n + Dr^n + \&c.$. Si igitur numerus $p$ minor fuerit, quam unus c
[TRUNCATED]
This text was produced by machine and has not been corrected by hand. Where it matters, read the scan. Confidence is the model's own, not an external check.