## Area between two curves using MAPLE...

DEAR SIR,

GOOD EVENING.

HOW TO FIND THE AREA BETWEEN THE CURVES  USING MAPLE?

## apply the following conditions to plot functions...

How I can edit and apply the following conditions to my plot functions

`######   I want to change q  (starting from 0.3) from 0.3 by .001 to 0.377 and plot 2D (u-q) ,(v,q), (u,v) and  plot3D (u,v,q)`

`######   I want to change q (starting from 0.37727) from 0.37727 by .001 to 0.390059 and h from 0.1 by .001 to 0.138462  and plot 2D (h-q)  and  plot3D (u,h,q),(v,h,q)`

I couldn't attach my file here, so I uploaded that here

## Are numerical methods and implicit, exact methods ...

Hi,

I am studying nonlinear differential equations, and came across an interesting one on maple's help page.  I made a post about this equation already, but I have decided to make a new post because the topic is slightly different than from the previous post.

The topic of this post is:

"Can numerical methods and exact, implicit techniques find false solutions?"

To make the discussion clearer, the rest of this post can be found in the maple file I created.

## Need Help on Integration...

Hi to all community. I am trying to integrate a lengthy-expression but could not get the result after waiting of 1 and 2 hours even. is there any way to control such integration

Integration_Help.mw

## Composition of polynomials...

A very simple question (by example):

Consider two polynomials g and h:

with(PolynomialTools):

g:=FromCoefficientList([1,2,3],x);

h:=FromCoefficientList([4,5,6,7],x);

What is the syntax for computing the composition of g with h? (As a polynomial.)

For instance, I would like to use CoefficientList on the result.

I know the @ operator and the subs command and have tried using them in various ways, but with no success.

(Of course, my question is general; the above is just an example.)

---

Edit: Additional question (which is my real question):

I'm writing a procedure that takes two polynomials g and h, and in which I define an unknown polynomial f. I want to compute its coefficients so that

f "composition" g = h

I write:

fCoeff:=seq(a[i],i=0..t) (to define the unknown coefficients. I can compute t.)

f := FromCoefficientList([fCoeff],x);

Then I would like to do something like:

comCoeff:=CoefficientList(f "composition" g,x)

If I have this, then I know how to solve for the unkown coefficients in f.

## When is evalDG needed when creating a tetrad etc i...

Given a metric, to compute quantities in the NP formalism one needs to specify a null tetrad. In the various examples in the help pages, sometimes the tetrad is specified simply as a list of 4 vectors, e.g., NT := [...] and sometimes evalDG is applied as in NT := evalDG({...]). Using the first format, Maple accepted NT as argument in NPSpinCoefficients but  NPCurvatureScalars(SpinCoefficients,NT) complained that the second argument wasn't a list of four vectors. When I used the second format, both commands returned the expected results. Why the difference?

RobinsonTrautmanSpinDG.mw

## How I can plot3d with two different conditions...

How I can plot3d function s. in the domain x ,y from -1300 to 200.

Thanks

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## Verify command with two variables ...

Hello. I want to use the command verify but with two variables. For example:

verify(x^2 + y^2, 0, {'greater_equal'});

but I get FAIL as an answer. I tried adding before the verify command assume(x, 'real'); assume(y, 'real');

but notihng changed.

Thanks for any help.

## Fractional expression simplification...

Dear people in mapleprims,

I haven't used maple for a long time.
By the way, I tried to modify a denominator part in an fractional expression, but I couldn't.

Original expression is

a:=-(I__22-X__2)/(I__11*I__22-I__11*X__2-I__12*I__21-I__22*X__1+X__1*X__2);

#And, I want to change this to the form

b:=(X__2-I__22)/((x__1-I__11)*(X__2-I__22)-I__12*I__21);

How can I do this?

Thank you in advance.

## How to plot a vector field so that small vectors h...

Hi,

I have managed to create the following plot.  It won't plot on the site's plotter:

fieldplot([1, y^2 + x], x = -10 .. 10, y = -6 .. 6, fieldstrength = fixed, color = abs(y^2 + x + 1))

I am trying to assign a colour gradient to the different vectors based on vector magnitude.  In the color option, I entered color= expresssion for the magnitude of the vectors

This only half worked.  It currently scales the colours such that the largest and smallest vectors are the same colour.  How do I assign a gradient such that the small magnitude vectors are one colour, and they then transition to another colour as their magnitude gets larger?

## How to get all solutions from a system of equation...

Hello. I am trying to solve this system of equations but I can't get Maple to show all solutions.

I have solve the system by hand and there are two more solutions (x=x, y=1) and (x=x, y=-1).

Thanks for any help !

## Why I do not get the expected results, when I try ...

Hello. I want to solve a 2X2 system using Maple. I have written this code but I do not get expected results.

restart;
with(DEtools);
with(plottools);
with(plots);
with(Algebraic);

F := -1 - y - exp(x);
G := x^2 + y*(exp(x) - 1);

sol1 := eliminate({F, G}, {x, y});

sol1 := [{x = RootOf(-exp(_Z)^2 + _Z^2 + 1), y = -exp(RootOf(-exp(_Z)^2 + _Z^2 + 1)) - 1}, {}]

But, the solutions are x=0 and y=-2 (I have solved the system by hand).

Any help?!

## How to rearrange a polynomial based on a variable...

I have a parametric polynomial which is defined based on the multiplication of different variables and I want to rearrange the polynomial based on specific variables. For example, suppose the polynomial is defined as follows:

a:= (1+x+y)(2x-yx+z)(y^2-zy)

and I want to have a based on first, and second orders of x, or even other variables. Thanks

## Cant figure out why my code wont run in Maple?...

Hi so ive been working on a few codes making Eulers method and RungeKutta and Taylor Series (second order) and I cant figure out why my code is giving me a weird output? I will attach my maple files here, I can post more information if you'd like. Also have no idea how to start for taylor series so any help with code on that would be appreciated!

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## How do I rearrange assignment to solve for a varia...

I have an assignment for Q that after subsequent other assignments and substitutions  results in

-XC1*R1^2/((R1^2 + XC1^2)*(R1*XC1^2/(R1^2 + XC1^2) + 12960.54302))

when I type Q.

I would like to solve this for XC1, for values of Q that make  XC1 is real.

How do I do this?  Can I rearrange this assignment?

I guess I could do something like this:

eq1:= -XC1*R1^2/((R1^2 + XC1^2)*(R1*XC1^2/(R1^2 + XC1^2) + 12960.54302))

solve(eq1=Q,XC1)

but Q as a function of XC1 is a derived from other relationships.

The worksheet probably makes what I'm asking more clear.    I was able to get the result, but I'm sure there is a better, more elegant  way to do what I needed to do...

Thanks

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Series-Parallel Conversion Equations as a function of Q

 • Q = Xs/Rs = Rp/Xp;
 • Rp := Rs*(Q^2 + 1);

Impedance Transpormation Equations

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