Re: N::meprec warning with Solve
- To: mathgroup at smc.vnet.net
- Subject: [mg86749] Re: [mg86696] N::meprec warning with Solve
- From: Curtis Osterhoudt <cfo at lanl.gov>
- Date: Thu, 20 Mar 2008 02:53:23 -0500 (EST)
- Organization: LANL
- References: <200803191021.FAA04722@smc.vnet.net>
- Reply-to: cfo at lanl.gov
Hi, Peter, At least on my system ( 6.0.1.0 on 32-bit Linux), the result of the Solve command is as follows (no application of N apparent): {{x -> -(1/4) - (1/2)*Sqrt[-(5/12) + 61/(3*((1/2)*(-223 + 9*I*Sqrt[10595]))^(1/3)) + (1/3)*((1/2)*(-223 + 9*I*Sqrt[10595]))^(1/3)] - (1/4)* Sqrt[(1/3)*(-10 - 244/((1/2)*(-223 + 9*I*Sqrt[10595]))^(1/3) - 2*2^(2/3)*(-223 + 9*I*Sqrt[10595])^(1/3) - 9/Sqrt[-(5/12) + 61/(3*((1/2)*(-223 + 9*I*Sqrt[10595]))^(1/3)) + (1/ 3)*((1/2)*(-223 + 9*I*Sqrt[10595]))^(1/3)])]}, {x -> -(1/4) - (1/2)*Sqrt[-(5/12) + 61/(3*((1/2)*(-223 + 9*I*Sqrt[10595]))^(1/3)) + (1/3)*((1/2)*(-223 + 9*I*Sqrt[10595]))^(1/3)] + (1/4)* Sqrt[(1/3)*(-10 - 244/((1/2)*(-223 + 9*I*Sqrt[10595]))^(1/3) - 2*2^(2/3)*(-223 + 9*I*Sqrt[10595])^(1/3) - 9/Sqrt[-(5/12) + 61/(3*((1/2)*(-223 + 9*I*Sqrt[10595]))^(1/3)) + (1/ 3)*((1/2)*(-223 + 9*I*Sqrt[10595]))^(1/3)])]}, {x -> -(1/4) + (1/2)*Sqrt[-(5/12) + 61/(3*((1/2)*(-223 + 9*I*Sqrt[10595]))^(1/3)) + (1/3)*((1/2)*(-223 + 9*I*Sqrt[10595]))^(1/3)] - (1/4)* Sqrt[(1/3)*(-10 - 244/((1/2)*(-223 + 9*I*Sqrt[10595]))^(1/3) - 2*2^(2/3)*(-223 + 9*I*Sqrt[10595])^(1/3) + 9/Sqrt[-(5/12) + 61/(3*((1/2)*(-223 + 9*I*Sqrt[10595]))^(1/3)) + (1/ 3)*((1/2)*(-223 + 9*I*Sqrt[10595]))^(1/3)])]}, {x -> -(1/4) + (1/2)*Sqrt[-(5/12) + 61/(3*((1/2)*(-223 + 9*I*Sqrt[10595]))^(1/3)) + (1/3)*((1/2)*(-223 + 9*I*Sqrt[10595]))^(1/3)] + (1/4)* Sqrt[(1/3)*(-10 - 244/((1/2)*(-223 + 9*I*Sqrt[10595]))^(1/3) - 2*2^(2/3)*(-223 + 9*I*Sqrt[10595])^(1/3) + 9/Sqrt[-(5/12) + 61/(3*((1/2)*(-223 + 9*I*Sqrt[10595]))^(1/3)) + (1/ 3)*((1/2)*(-223 + 9*I*Sqrt[10595]))^(1/3)])]}} Hope that helps! C.O. On Wednesday 19 March 2008 04:21:27 Peter Breitfeld wrote: > consider the function: > > f[x_] := (x^4 + x^3 + x^2 + 5)/(5 x^2 + 5 x + 5) > > lsg=Solve[f[x]==0,x] > > gives the warnings: > > N::meprec: > "Internal precision limit $MaxExtraPrecision = 50.` reached while > evaluating Im[61/(3\(<<1>> <<1>>)^(1/3))+1/3\ (1/2\(<<1>>))^(1/3)]." > > How can this happen if no Reals are used? Why is N called? > > BTW the results of Solve are correct > > Gruss Peter -- ========================================================== Curtis Osterhoudt cfo at remove_this.lanl.and_this.gov PGP Key ID: 0x4DCA2A10 Please avoid sending me Word or PowerPoint attachments See http://www.gnu.org/philosophy/no-word-attachments.html ==========================================================
- References:
- N::meprec warning with Solve
- From: Peter Breitfeld <phbrf@t-online.de>
- N::meprec warning with Solve