MathGroup Archive 2006

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Closed Form solution too much to hope for?


Assuming mean(x) is about .75, here is an empirical formula
that might be useful to you:

In[1]:=x[c_,d_,n_]:=Sqrt[c](d-1)(2d-1)+c^(1/n)d(2d-1)-
(2(d-1)d(-2n+Sqrt[2]Sqrt[36c+n(9+2n+9Log[4/3])-9(1+Log[2])]))/3

In[2]:=x[c,0,n]

Out[2]=Sqrt[c]

In[3]:=x[c,1,n]

Out[3]=c^(1/n)

In[4]:=x[.5,.6,9]

Out[4]=0.88615

In[5]:=FindRoot[d x^n+(1-d)x^2==c /. c -> .5 /. d -> .6 /. n ->
9,{x,.5}]

Out[5]={x -> 0.880133}


hth

V.Astanoff


  • Prev by Date: Homotopic algorithm to solve a system of equations
  • Next by Date: Re: How to get the maximums of a curve
  • Previous by thread: Re: Homotopic algorithm to solve a system of equations
  • Next by thread: Re: How to get the maximums of a curve