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                | LewisLabAZ | Posted - 07/20/2004 : 2:01:10 PM Is the root solving function on Origin 7.5 capable of handling higher order equations such as a quartic or a quintic? We want to solve these equations for x and do not want the coefficients as fitting parameters in our user defined NLSF fit.
 Thank you very much
 Lewis Lab
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                | 4   L A T E S T    R E P L I E S    (Newest First) | 
              
                | LewisLabAZ | Posted - 07/23/2004 : 7:13:34 PM Thank you easwar and rdremov for the replies. We really appreciate the attention.
 Lewis Lab
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                | rdremov | Posted - 07/21/2004 : 2:57:04 PM Quick try of the tool:
 find_roots "(x-1)*(x-2)*(x-3)*(x-4)*(x-5)" 0 10;
 will correctly find all five roots: x = 1, 2, 3, 4 and 5
 
 Roman
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                | easwar | Posted - 07/21/2004 : 2:39:06 PM Hi Lewis Lab,
 
 Perhaps I did not understand your question correctly. What this tool does is just a numerical bisectional search for roots, with some preset accurarcy (how close is the y value to zero). So as long as a numerical solution is possible, it should find the root as long as the equation can be computed - no matter whether it is a cubic or quintic etc. The tool does not do any algerabic root finding, if that is what you are looking for.
 
 Are you having trouble with a particular equation/expression? Did you first try generating values with your expression in a column, then plot that colummn to see if any roots would exist in your X range?
 
 Easwar
 OriginLab
 
 
 
 
 Edited by - easwar on 07/21/2004  2:39:44 PM
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                | easwar | Posted - 07/20/2004 : 4:42:15 PM Hi Lewis Lab,
 
 The objective of that "tool" in the File Exchange area was to provide a tool for finding roots of simple equations using bisection method. Solving quintics seems to be a rather complex problem as ca be seem from this page:
 http://mathworld.wolfram.com/QuinticEquation.html
 and this tool on the File Exchange area is not capable of doing that.
 
 Easwar
 OriginLab
 
 
 
 
 Edited by - easwar on 07/20/2004  4:42:41 PM
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