- #1

Woland

- 18

- 0

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.