On MSFT site, it is said that the number formatting of the polynomial function in the graph is not precise enough and that we can correct this by changing the number of decimals.

For example in the calculation_trendline_jpr73.xlsm
(see http://www.excelforum.com/excel-gene...equations.html),

the function displayed was: y = 1E-07x4 - 0.0001x3 + 0.0587x2 - 10.43x + 867.75
but in reality it is :
y = 0.0000000999999999997314x4 - 0.000100000000000026x3 + 0.0586999999998742x2 - 10.4299999999427x + 867.749999993586

Now what I don't understand is why when we use LINEST we obtain this:
y= 0.000000137525200690634x4 - 0.000146864975803026x3 + 0.0586512659056951x2 -10.4304873662204x +
867.747984421906

I mean it is close but it is not the same. What explains the difference ?

Thanks in advance