## Solving Differential Equation System...

Hi everyone, Could you please have a look at my maple file. Im trying to solve a set of 4 differential equations but maple takes ages to solve and doesnot give the answer at the end either. The reason can be that the equations have to high power. Do you know any other dsolve method I can use or anything I can do to fix this problem? Thank you very much! Jinny View 3868_Pressure drop 2.mw on MapleNet or Download

## Scatter Plot and Function on same Axes...

Hi, I created a scatter plot in a Maple 11 Worksheet by creating a list (below) and right clicking and using the Plot tools. However, I want to graph a function on the same scatter plot. Can this be done? L := [[32, 6], [48, 14], [64, 24], [80, 38], [96, 55], [112, 75]]

## Number System Conversion...

Is there a package available in Maple that converts between number systems ? e.g., binary, octal, hexadecimal. v/r,

## Requesting Feedback On A Procedure...

Thanks to all the wonderful and timely help I received concerning my previous troubles with the LegendreP function. It was all helpful. I think I'm very bad at procedures, but I struggled in an effort to gain more personal knowledge, in addition to solving this problem and came up with a very simple and rudimentary procedure. It is called P[legend](l,m), where l and m are the two arguments received in that order. Can anyone look at this procedure and suggest improvements for efficiency, aesthetics (more elegant simpler methods), possible bugs, etc. Your critiques on my effort would be greatly appreciated.

## Output with leading digit in "one's" spot (instaea...

Somewhere along the line, my output format switched to display the most significant digit in the tenths decimal place. I can't figure out how to change it back to the unit (one's) decimal place. Anybody know where to find this setting? Thanks, Brad

## MultiVariate Directional Derivative...

None of these suggestions allow for the evaluation of the directional derivative at a particular point, in this case (1, -2, 3). (I cannot make the command line suggestion work at all - error: "expects its 2nd argument, v, to be of type ('Vector')(algebraic), but received [x, y, z]") Surely, evaluation can be done without an additional substitution statement. John Vawter

Hello I have a very strange math question and I want to verify the result with MAPLE but I really have no idea why (we have no "Maple" notes with our course yet)... I want to find the gradient of exp(x*y*z)*cos(x*y^3*z^2) and exp(x*y)*cos(x*y^3*z^2) at point (0,0,0) with direction 2i-3j+k. It seems like a very strange question, the gradient at (0,0,0) of both functions seem to give 0. I don't really care about the direction, if only I could verify the gradient at (0,0,0), it would be great. Thx

## density plots...

Hey, I'm trying to make a density plot for the hydrogen wave functions in maple I only see how to make a density plot in cartesian coordinates, but I want to make a density plot in polar or better in 3D spherical coordinates.

## MultiVariate Directional Derivative...

I am trying to get the directional derivative for a 3 variable (x,y,z) function. Maple is saying: Error, (in Student:-MultivariateCalculus:-DirectionalDerivative) include points for only the x and y coordinates for entry DirectionalDerivative(x*exp(y)/(3*z^2+1), ([x, y, z]) = ([2, -1, 0]), [1, -2, 3]) Any help would be greatly appreciated. Thanks, Dave

## Help Using The LegendreP Function...

Does anyone know how to get the function

LegendreP(1,1,cos(theta)) to return the value of sin(theta) ?

I'm using the associated Legendre function.

I think the first 1 represents the degree of the polynomial, and the second 1 stands for the derivative order. (I'm not sure).

When using the associated Legendre function, LegendreP(u,v,cos(theta)), I get the expected results only for certain combinations of the values of u and v.

The problem has to do with the eveness and oddness of u and v.

I also tried manipulating the global variable, _Env...? (Can't recall it's full name).

## extracting data to excel...

Hi I was wondering.. I am solving a set of differential euqations and i get my table of values: soln3:= dsolve(... I would like to extract those values to excel... Is there a command for that? Thanks! Elinor

## maximum likelihood estimation...

Does anyone know how to perform maximum likelihood estimation in maple 10 or 11 with multiple unknown parameters? If pop100 is a vector of floats, then code like: `MLE(LogNormal(mu, sigma), pop100)` yields this error message: `Error, (in Statistics:-MaximumLikelihoodEstimate) when calling '`one of {op, module () local OptionsTab; export FisherInformation, Information, Likelihood, LikelihoodRatioStatistic, LogLikelihood, MaximumLikelihoodEstimate, Score, GetValue, ProcessOptions; LogLikelihood := module () local OptionsTab; export ProcessOptions, MakeProc, GetValue; OptionsTab := table([(OptionParms)=(table([(samplesize)=[deduce, {posint, identical(deduce)}],(weights)=[Array(1..0, []), {rtable}],(ignore)=[false, {truefalse}]])),(PositionalParms)=(table([]))]); ProcessOptions := proc (parms::list, other::list, opts::table) return :-ProcessOptions(0,other,Statistics:.`