Intersection of two curves using fsolve command...

Question: You will observe that the two curves intersect at one or more places in the displayed region. Use fsolve to find the (x; y) coordinates of all the points of intersection in this region.

In theory this question has a very simple answer, but i am struggling no end finding it.

P1 := y^2 = x^3+x^2

P2 := y = 2*x+1

This is what the graph looks like when plotted, and as we have already got the two equasions assigned as H and J, i just type in fsolve({P1,P2})?

Apparently not, as this returns {x = 4.048917340, y = 9.097834679}, which is correct, but is only one of three points of intersection, and just so happens to be the one not shown in my plot (although it is still a valid point of intersection) and i need the ones within the region i have set for the graph (x=-1..2 and y=-1..1).

How do i get maple to show me the two points of intersection i need using the fsolve command?

I've tried rearranging the equasions for y, rearranging for x, adding an option to solve for x [fsolve({P1,P2},x) but this returned an error] and am pretty stumped. For something so seemingly simple i dont really know where to turn.

Thank you :)

How to use the product command in the following wa...

When i input: i get returned.and with this i have no idea what im supposed to do. I dont understand what it means, how to correct it or how to actually answer the question using the information.

This is what i am returned with when i try to input a sequence using my previous result.

Could someone please put me on the right tracks and help me with this problem?

Thank you

Need result using Laplace transformation using num...

Helo dearz!

I want to find the inverse laplace transfrom (numerically) of the attached file of solution u and v for any values of M. I am waiting for your positive response.

Help_v2.mw

How to construct a Matrix ?...

Hi,

• N is the number of row, about 10^4 in real applications
• P is the number of columns (about 5)
• A and B are two NxP matrices
• C is the Nx(2P) matrix defined by
• its 2*k-1 th column is the k th column of A
• its 2*k th column is the k th column of B

What is the fastest and less memory consumming way to construct this matrix C ?

How to solve a problem foat(infinty)...

كيفية حل مشكلة فوات (إنفينتي)

Want to solve the system of algebraic equations...

Hello dear!

Hope everyone is fine. I want to solve the system of algebraic equations. The answer of c[i]'s should be in term of q. Please see the attachment and fix the problem for any value of M. I am waiting your positive response. Thanks in advance.

Help.mw

function call does not work...

fgh := proc (x) options operator, arrow; [x, x^2, x^3] end proc;

sol := proc (x) options operator, arrow; min(`~`[Re](select(proc (t) options operator, arrow; is(abs(Im(t)) < 0.1e-19) and is(0 < Re(t)) end proc, fgh(x)))) end proc;

eval('sol(x)', [x = X]);

eval(%, X = 1)

Why does this not work?

Vertices of Cuboid with Geom3D...

Is there a way to determine the coordinates of all the vertices of a cuboid using geom3d?

The graphic of the cuboid is created with

A:=(cuboid([1,1,2],[3,4,5]), orientation [27,78],lightmodel = light4, shading = none, transparency =.85,scaling = constrained, axesfont = [bold, roman, 18], axes = normal):

And the vertices are self-evident, for example

B:= pointplot3d({[3,1,5]}, symbol = solidsphere, symbolsize = 18, color = red):

One geom3d ....

geom3d[point](P,1,1,2): geom3d[point(Q,3,4,5): geom3d[distance](P,Q);

gives the lengths of the diagonal of the box.  Is there a way to get geom3d to list the coordinates of the 8 vertices of a cubeoid?

Does anyone know if there exist a script in JAWS for MapleSoft?

Reducible RootOf...

I have a polynomial of 4th order and I wanted to use allvalues on the RootOf expression. It then says:

Error, (in evala/Normal/preproc) reducible RootOf detected.  Substitutions are {RootOf(4678560000000000000000000000000000000000+(16573041*CO^2+70122975000000000000*CO-623180900000000000000000000000000)*_Z^4+(-19887649200*CO^2-82987335000000000000000*CO+745755960000000000000000000000000000)*_Z^3+(5966294760000*CO^2+23851989000000000000000000*CO-221858784000000000000000000000000000000)*_Z^2+(417684600000000000000000000*CO-757598400000000000000000000000000000000)*_Z) = 600, RootOf(4678560000000000000000000000000000000000+(16573041*CO^2+70122975000000000000*CO-623180900000000000000000000000000)*_Z^4+(-19887649200*CO^2-82987335000000000000000*CO+...
Error, (in allvalues) numeric exception: division by zero

So apparently the expression is reducible but how do I do that?

Numerically Solving y'=f(x,y)...

I am trying to numerically solve y'=f(x,y) with y(0)=y0, where f is a solution to a PDE. In this case, f is a numeric approximation itself. I attempted to add this equation to the system of equations when finding f, but pdsolve will not accept an equation of this form. Then, in attempting to use f in dsolve, I get an error, stating that the input system must be an ODE system, found {y(x),f(x,y(x))}.

Is there any way to use dsolve or pdsolve to generate y(x)? Or will I have to stick with using more classical methods like RK4?

Exporting high quality plots from Maple to Word Te...

I have in my Maple documents many good quality plots resulting from simulations. I need to export (or paste) them to templates of transactions in Word without loosing quality, and beeing flexible to some degree to fit the dimension.

Until now when I paste such plots the quality is lost and especially on descripltion on axes (vertical).

What I have to do? Do I need to go throuhg pdf format ?

Hi everybody,

I use the Grid[Launch] function  (Windows 7, Maple 2015) to distribute many similar computations over all the processors my machine has.

Question 1

My machine is a 4 processors one (not hyperthreaded).
When it was equiped with Windows XP and I was using, let's say 2 proc., the performance manager showed that two processors among 4 were charged up to 95%-100% while the others remained around 0 %.
In this case (my problem is perfecly scalable), the elapsed time was exactly half it was when I used only one proc (and twice as large as the time obtained with 4 proc).

Now I'm working with Windows 7.
This behaviour puzzles me : if I use 2 procs among four and look to the performance manager, all the 4 procs are partially charged. It looks like Window 7 was distributing itself the computations ?
As a result (?), running on 4 proc no longer takes 25% of the elapsed time on 1 proc, but "only" 40%.
Could it be that some inner "dispatching task within processors" Windows 7 could have, might interfere with the distribution of tasks  Grid[Launch] does ?

If Windows 7 really has some "task managing procces", is it possible to switch it off ?

Question 2

Same context as previously.
I run the same code (search of a local maximum of a function where some of its parameters are randomly valued ; the sample of these parameters hase size 10000) over 4 proc.
On order to save intermediate results I wrote a loop within it I send blocks of 500 computations at the same time over the 4 proc.
This loop is executed 5 times (5*500*4 = 10000)

I observe that after each step of the loop the memory used is increased by a rather constant amount. It looks like if a 4 proc computation of 500 optimizations was costing N Mega Bytes, and that the memory was increased by N MB each times the loop is executed.
At the very end the computational time can dramatically slow down because of the amount of the memory used.

More precisely my pseudo code looks like this :
for step 1 to 5 do
Grid[Launch](MyCode, numnodes=4, imports=[BlockOf2000data], ...):

# MyCode uses only one quarter of this 2000 data block depending on the processor number it runs on
end do:

Does it exist a way to clean the memory just before the "end do" command in order to avoid it to grow continuously ?

Any contribution will be highly appreciated.

extract common factors from expression after colle...

Often after using collect(expression,x) the prefactors of x are within a bracket but typically contain factors in each term of the bracket that are equal and not pulled out of the bracket. Is there a way to ask maple to automatically factor out these after collecting?

I hope it is clear what I mean...

How to properly determine roots when the solution ...

Hello everyone,

First I want to thank you for paying attention to my post.

I'm trying to determine the maximum of the following function:

Maple Code:

(1/4)*(-1/4+alpha*(-1+b)*e^2+((1-b)*alpha+(1/4)*b)*e)^2/((-1+e)^2*(b*e-1)*alpha*e*(-1+b))(1/4)*(-1/4+alpha*(-1+b)*e^2+((1-b)*alpha+(1/4)*b)*e)^2/((-1+e)^2*(b*e-1)*alpha*e*(-1+b))

e is my variable and I want to study it in [0,1[. I have a several parameters restriction like b in [0,1[ and alpha>1.

When I value this function for specific values (b=0.1, alpha=4 for instance) I get the equation and its associated graphic representation:

Maple Code:

-0.6944444445e-1*(-1/4-3.6*e^2+3.625000000*e)^2/((-1+e)^2*(.1*e-1)*e)

I'm only interested in the domain where e is betweeen 0 and 1. I clearly on the graph see that there is a maximum and when 1) I compute roots of the expression I get 2) following solutions:

1)

2)

0.9324708634, 0.07447358108, 0.6965691592, 1.345632810,

-0.07419084270.

Here: 0.6965691592 corresponds to the maximum I'm looking for.

So now when I try to get a generalization of this function according to my parameters and when I compute the first derivative with respect to e

1)

2)

3)...

the last is very big so I do not write it here.

To sum-up: I see that the solution I'm looking for exists but when it comes to use parameters I cannot define correct roots.

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