Re: Polylog equations
- To: mathgroup at smc.vnet.net
- Subject: [mg84987] Re: Polylog equations
- From: danl at wolfram.com
- Date: Tue, 22 Jan 2008 01:50:56 -0500 (EST)
- References: <fn21oa$in5$1@smc.vnet.net>
On Jan 21, 6:04 am, Valeri Astanoff <astan... at gmail.com> wrote:
> Good day,
>
> Given these polylog equations:
>
> In[1]:= Assuming[0 < x < 1,
> Solve[PolyLog[3/2,x]==y && PolyLog[5/2,x]==z,z,x]]
>
> Out[1]= {{}}
>
> what is the best way to get z(y)?
>
> Thanks,
>
> V.Astanoff
Could iterate Solve for this.
In[8]:= Solve[PolyLog[5/2,x]==z /. Solve[PolyLog[3/2,x]==y,x]]
Solve::ifun: Inverse functions are being used by Solve, so some
solutions may
not be found; use Reduce for complete solution information.
Solve::svars: Equations may not give solutions for all "solve"
variables.
5 3
Out[8]= {{z -> PolyLog[-, InverseFunction[PolyLog, 2, 2][-, y]]}}
2 2
Daniel Lichtblau
Wolfram Research