Re: How to find Complex roots !!
- To: mathgroup at smc.vnet.net
- Subject: [mg26188] Re: How to find Complex roots !!
- From: "A. Ciarkowski" <aciark at ippt.gov.pl>
- Date: Thu, 30 Nov 2000 22:02:08 -0500 (EST)
- Organization: http://news.icm.edu.pl/
- References: <8uqumr$qp7@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Try this (here assumed n = 3 and a = 5):
g[x_] := x^3 + x^2
Solve[(g[x] + I f x - a /. f -> Normal[ Series[ Cos[x] + Cosh[x],
{x, 0, 2} ]]) == 0, x ]
a=5;
Table[ FindRoot[ g[x] + I(Cos[x] + Cosh[x])x - a == 0,
{x, %%[[i, 1, 2]]} ], {i, 3} ]
(* Verification: *)
g[x] + I(Cos[x] + Cosh[x])x - a /. %
Clear[a]
This can be simply adapted to a different n < 5, by suitably
modifying g[x], replacing {x, 0, 2} in the second command
by {x, 0, n - 1} and {i, 3} by {i, n}.
Adam