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Main Question or Discussion Point
Hello all,
I am trying to extract the 2nd degree polynomial coefficients from a curve of best fit applied in EXCEL. I know how to do it (http://spreadsheetpage.com/index.php/tip/chart_trendline_formulas)
2nd Order Polynomial Trendline
Equation: y = (c2 * x^2) + (c1 * x ^1) + b
c2: =INDEX(LINEST(y,x^{1,2}),1)
C1: =INDEX(LINEST(y,x^{1,2}),1,2)
b = =INDEX(LINEST(y,x^{1,2}),1,3)
Iv done it before, but for some reason it is not working out for my particular data set. I keep getting errors or zero for my coefficients. If I do the regular best fit using the trendline option, it works.
I get: y = 2E+16x2 + 1E+11x + 3.033
I am attaching my data set.
Does any one know if there is something wrong with my method? Perhaps Im forgetting something.
Thanks.
I am trying to extract the 2nd degree polynomial coefficients from a curve of best fit applied in EXCEL. I know how to do it (http://spreadsheetpage.com/index.php/tip/chart_trendline_formulas)
2nd Order Polynomial Trendline
Equation: y = (c2 * x^2) + (c1 * x ^1) + b
c2: =INDEX(LINEST(y,x^{1,2}),1)
C1: =INDEX(LINEST(y,x^{1,2}),1,2)
b = =INDEX(LINEST(y,x^{1,2}),1,3)
Iv done it before, but for some reason it is not working out for my particular data set. I keep getting errors or zero for my coefficients. If I do the regular best fit using the trendline option, it works.
I get: y = 2E+16x2 + 1E+11x + 3.033
I am attaching my data set.
Does any one know if there is something wrong with my method? Perhaps Im forgetting something.
Thanks.
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