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Re: Solving Polynomial equation

  • To: mathgroup at
  • Subject: [mg100968] Re: [mg100901] Solving Polynomial equation
  • From: Murray Eisenberg <murray at>
  • Date: Thu, 18 Jun 2009 20:49:00 -0400 (EDT)
  • Organization: Mathematics & Statistics, Univ. of Mass./Amherst
  • References: <>
  • Reply-to: murray at

Let's say your Excel spreadsheet is abc.xls and it's in directory 
e:\temp.  Assume it has column headers a, b, c in row 1 and then the 
data in columns below. (You didn't mention values of the constant c in 
your quadratic, but I'll assume you have those, too; if not, you can 
readily modify the following.)

   (* say where file is *)

   (* import spreadsheet data *)
   abc = Import["abc.xls",{"Data",1}]

   (* strip off first element, which is column headers *)
   abc = Rest[abc]

   (* set up form of quadratic eq'n in pure function... *)
   (* ... and map onto the abc values *)
   Solve[#[[1]] x^2+#[[2]] x + #[[3]]==0,x]&/@abc

As usual in Mathematica, you'll get the solutions in the form of lists 
of rules, one list for each {a,b,c} triple.

kosal lee wrote:
> Hello
> I need help and I am new to Mathematica.
> Suppose I want to solve for the equation:  aX^2 + bx +c ==0, however
> I have a list of parameters a and b in my microsoft excel where a and b are columns and its value are in rows.
> I dont want to key every a and b each time to find the root of above equation.
> Are there anyway to tell Mathematica to import each a and b value from excel, put it in the above equation, and find its root
> and it export the list of results back to excel?
> Thank you.
> Best Regards,
> Kosal

Murray Eisenberg                     murray at
Mathematics & Statistics Dept.
Lederle Graduate Research Tower      phone 413 549-1020 (H)
University of Massachusetts                413 545-2859 (W)
710 North Pleasant Street            fax   413 545-1801
Amherst, MA 01003-9305

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