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1-Visitor
August 20, 2015
Question

How do i know which coefficients go with which independent variables in a second order polynomial with 3 independent variables?

  • August 20, 2015
  • 3 replies
  • 1736 views

How do i know which coefficients go with which independent variables in a second order polynomial with 3 independent variables? I have extracted 10 coefficients but now want the equations to use elsewhere.

3 replies

19-Tanzanite
August 21, 2015

Which version of Mathcad, and how did you generate the polynomial coefficients?

Archie511-VisitorAuthor
1-Visitor
August 21, 2015

I have Mathcad 15.  I created a matrix M with the 3 independent variables (W,X,Y) then used regress with the dependent variable Z and order 2 (Eq2 = regress(M,Z,2) ) .  When I display Eq2 = ...  I get the vector with the coefficients list after the 3,3,2 but when I use these the results are not close but with regress with order 1 and the same data the results are somewhat close.

19-Tanzanite
August 23, 2015

In which case, see the attached worksheet.