Polynomial of Degree [ ] calculates polynomial equations from labeled or unlabeled two-column data matrices. The result is a polynomial of the specified degree that is the best fit to the data in the least-squares sense. For the polynomial fit, the x column appears first.
To find the best fit by a polynomial of second degree to the set of points
Matrices + Reshape
0,.64,.5,.09, 1,.04, 1.5,.49, 2, 1.44,![]()
To find the parabola that best fits the data, make the following choices.
Statistics + Fit Curve to Data
Select Polynomial of Degree [ ], enter UserInput2, click OK
, Polynomial fit: y = .64 - 1.6x + 1.0x2
, Polynomial fit: y = 5.9971 - 8.5243x + 2.2786x2
You can plot the points and polynomial on the same graph. You will notice that these points were chosen such that they lie on the parabola.
Plot 2D + Rectangular
,.64 - 1.6x + 1.0x2
dtbpF2.9992in1.9995in0ptPlot
Plot 2D + Rectangular
, 5.9971 - 8.5243x + 2.2786x2
dtbpF3in2.0003in0pt
You can also fit data with polynomials of higher degree.
Statistics + Fit Curve to Data
Select Polynomial of Degree [ ], enter UserInput3, click OK
, Polynomial fit: y = 8.1143×10-2 +1.4114x + 9.1143x2 -5.92x3
dtbpF2.9992in1.9995in0ptPlot
Statistics + Fit Curve to Data,
Select Polynomial of Degree [ ], enter UserInput4, click OK
, Polynomial fit: y =
-
x +
x2 -
x3 +
x4
dtbpF3in2.0003in0pt