## how to use numerical method like runge kutta to so...

Hi, I am trying to find a solution to this following maximization problem: pi[a1]:=Q*log(t)*(e[q]) - ( P*(1/log(t))*(1/(1- (e[q])))) - log(y)*log(t)*(e[q]*s[q]+(1-e(q))*s[p]); maximize pi[a1] with respect to t and e[q]. I tried analytical method but it seems that there is no closed form solution. pi_a1[diffwrtp_t]:=(diff(pi[a1],t)); pi_a1[diffwrtp_eq]:=(diff(pi[a1],e[q])); solve({pi_a1[diffwrtp_t] =0, pi_a1[diffwrtp_eq]=0 },{t, e[q]}); Can someone please advice me how to solve the differential equation stated above so that I can find a relationship between t and e[q] and t and y.

## Help with printing...

Hello, I'm still a new user and I have been unable get MAPLE to print with a result that looks like the original MAPLE file. I know the solution is probably something simple but I can't figure out what it is. I have just uploaded 2 files; GeorgePaper1.mw and GeorgePaper1.pdf. The latter is a file printout of the former. I'd sure appreciate it if someone could take a look at these 2 files and tell me what I'm doing wrong. -Thank you.

## upper limit on "delay" options for plotter?...

When using the Plotter element in a Maplet, one of the options is (copied from the help file): delay = posint The delay in milliseconds between frames. The default value for this option is 100. So far, if I set this above 1000, the animation will not play. 1000 works and anything below it. Does this mean I cannot have my animation play slower than one second intervals between frames? If this is the upper limit, does anyone have a suggestion for how to get around this? One thing I was thinking was using the Student[Calculus1][ApproximateInt] command (this is what I'm animating) with the partition value set at different intervals corresponding to a function, t, 2*t, 4*t, etc., just like the actual animation does. But I could have my plotter updated manually using a time delay function that Will gave me previously on here. That's a lot of extra code, though; delaying the plot speed even more would work much better.

## Programming If then elif else...

Hi all,

I'm having a dickens of a time trying to get the following simple conditional statement to work:

> restart;
>
>
> p := 6;
> q := 8;
> delta := 4;

> if ((q>0) and (p<0))then print(Node)
elif((p=0) and (q>0))then print(Center)
else print(Spiral)
end if;

Error, Got internal error in Typesetting:-FI : "'_Inert_DELAYBOOLEAN' is not a valid inert form"
Typesetting:-mambiguous(if ((qgt0)and(plt0))then printApplyFunction(Node)

After I compute the values of p,q,and delta I want a ptinted line to tell me the type of Critical Point I have. I am using Maple 10 Student with WIN XP Pro

## How to solve the problem of least square ?...

i need to solve the equation in method in least square; i have one equation e.g.f(x)=a*x^2-b*x-c, but i need use it two times in one equation,like g(x)=f(x1)-f(x). f(x1) put the value x1 in equation f(x),the behind is not change.so the equation like this : a*x1^2-b*x1-c-a*x^2-b*x-c if i input the equation g(x):=f(x)-f(x)the input the value a,b,c.got the 0. it's not my need. who can tell me how to solve the problem?

## Visualization of a linear system of more than one ...

Hi people, I would like to know how to obtain in maple (to add this in a variable in mapleTA) the next thing: a system like this: {x+2y=0, x+4y+3z=5, x+y+z=0} in a good presentation way, I mean, If I do MathML:-ExportPresentation({x+2y=0, x+4y+3z=5, x+y+z=0}) and I use the resultant code in mapleTA, I obtain the system in a inline way, but I want it like this: x+2y=0 x+4y+3z=5 (here a big "}" englobing all) x+y+z=0 How is it possible using only maple? Thanks

## Generating unevaluated MathML...

I want to generate MathML code. I'm using Maple 9.5. However I want the generated code not to evaluate the expression. For example:

> codegen[MathML](5^4);
<math xmlns='http://www.w3.org/1998/Math/MathML'>
<semantics>
<mn xref='id1'>625</mn>
<annotation-xml encoding='MathML-Content'>
<cn id='id1' type='integer'>625</cn>
</annotation-xml>
<annotation encoding='Maple'>625</annotation>
</semantics>
[/itex]

while what I want is:

<math xmlns='http://www.w3.org/1998/Math/MathML'>
<semantics>
<mrow xref='id3'>
<msup>
<mi xref='id1'>5</mi>

## Printing in Maple 10...

Hi When I try to print in Maple 10.05 having set the zoom factor to below 100% (e.g. 75%) the print is still in 100% zoom. How do I print using a smaller zoom? This was possible in Maple 10 Classic and Maple 9.5 By the way, I am using Ubuntu Linux 6.06 Regards

## Maple returns e instead of exp...

Hi all.. I am probably overlooking a switch or setting in Maple(10)Win XP, but when I do a calculation such as: yh:=c1*x1*exp(-1.5*t)+c2*x2*exp(-1.44*t); Maple returns: yh:=c1 x1 (e)^((-1.5000 t))+c2 x2 (e)^((-1.4400 t)) Which is correct but Maple does not recognize the (e)^(-1.44*t) as the exponential when I try to use it in future calculations. Is there a setting I have missed or is this how Maple handles exponentials? TIA Larry Ciak aka malt_master@comcast.net

## Complex differential equations...

Hi, I am trying to solve a first order differential equation numerically using dsolve. The equation is of the form dx/dt = k1 x + k2 |x|^2 x where x(t) is a complex valued function and k1 and k2 are complex constants. I get the following warning/error from maple10 Warning, abs is not differentiable at non-real arguments For this equation dsolve only gives me the solution for relatively short times (t ~1 or 2) and I know there is a solution valid at large times >>1. Obviously I could cast this equation into a system of 2: one for the real part and the other for the imaginary part.

## Simultaneous Algebraic Equations...

Given N-1 independent (not necessarily linear) equations in N variables, how do I tell Maple to find solutions in terms of a specific variable? For example: with(RealDomain); eq1:=x-1=a*cos(theta); eq2:=x+1=a*sin(theta); I want to find a and theta in terms of x: a=sqrt(2*x^2+2), theta=arctan((x+1)/(x-1)) solve({eq1,eq2},[a,theta]) appears to give me solutions based on elimination of x.

## Hiding the axis' scale when plotting?...

Hello! Another newbie question. How do I prevent Maple from displaying the actual numbers on the x-axis and y-axis in a plot? I've looked around in Help, but couldn't find anything useful... Thanks for your interest! Carolus