Nonlinear
![Fig1a = ListPlot[data, PlotRange-> {{0, 300}, {0, 30}}, Frame→True, Prolog→AbsolutePointSize[6], PlotStyle→Hue[.8]] ;](../HTMLFiles/MATH5_TUT1_473.gif){kind=small}
![[Graphics:../HTMLFiles/MATH5_TUT1_474.gif]](../HTMLFiles/MATH5_TUT1_474.gif)
Call for nonlinear fitting
Make sure that there is no predefined values for our variables
![Clear[a, b, c]](../HTMLFiles/MATH5_TUT1_476.gif){kind=small}
![nlfex1 = NonlinearFit[data, a + b x + c/x^2, {x}, {{a, 1}, {b, 1}, {c, 1}}, MaxIterations→1000, Method→Automatic]](../HTMLFiles/MATH5_TUT1_477.gif)
Define the function using the values from the previous command
![cv[x_] := 1.58538 - 870.703/x^2 + 0.0940781 x](../HTMLFiles/MATH5_TUT1_479.gif){kind=small}
If x_ is not working try x in cv[x_]
![Fig2 = Plot[cv[x], {x, 14, 300}]](../HTMLFiles/MATH5_TUT1_480.gif){kind=small}
![[Graphics:../HTMLFiles/MATH5_TUT1_481.gif]](../HTMLFiles/MATH5_TUT1_481.gif)
We use the Show command to superimpose figures
![Show[{Fig2, Fig1a}, Prolog→AbsolutePointSize[12]]](../HTMLFiles/MATH5_TUT1_483.gif){kind=small}
![[Graphics:../HTMLFiles/MATH5_TUT1_484.gif]](../HTMLFiles/MATH5_TUT1_484.gif)
Problem 3. - Consider the following data and find a fit and plot the data and the best fit function
data2 ={{220,.642},{250,.759},{275,.861},{300,.952},{325,1.025},{350,
1.085},{380,1.142},{400,1.177}}
| Created by Mathematica (September 7, 2006) |  |