Hello everyone.

Now, I am studying nonlinear fitting method through help file of maple. Unfortunately, I'm not getting good fit using NonliearFit. The following is my psocedure:

> restart;
> with(Statistics);
> y := 1/(3.6+2.3*x)+17.6*exp(-0.2*x);
> fy := unapply(y, x);
> for x to 10 do fy(x) end do;
14.5791527795
11.9195840297
9.75432289049
7.98631476846
6.54090333018
5.35848939402
4.39086798669

A method of fitting a curve to data points so as to minimize the sum of the squares of the distances of the points from the curve.
For example (yei,x1i,x2i,x3i,x4i) is experimental data and relevant function is y=f (x1,x2,x3,x4), some unnkown parameters

(a1,a2,a3,a4) can be solved by minimizing the sum of squares of residues.
Procedure is:
ry:=(yei-y)^2;
Tr:=sum(f, i = k .. n);
da1:=diff(Tr, a1);da2:=diff(Tr, a2);da3:=diff(Tr, a3);da4:=diff(Tr, a4);

Hello, everyone.

Here is a simple question.

How can I solve an equation containing a logarithmic function, for example:
eq:={40=53802.8616296/V-4421522.681759509154376431238971030890884/V^2-34696412.12593013477367899170424836286055/V^3-68770455564.45999796126160810938763183857/V^4+403332559275.4141930212434442368214769780/V^5+958128028485.0130104382506076504882209562/V^6-26140204752481.13476652750626233649550628/V^7+17375263330.60863159106251286006887257238*ln(V)/V^4,1258*0.9<V<1258*1.1}