MaplePrimes Questions

solve Differential equation "a-y=y' bc" use maple 17

the result is y(x)=a+_C1e^-(1/bc)

but the correct result  isn't y(x)=a-_C1e^-(1/bc) ?

Thank you in advance for your help

 

Hi :)

I have a Macbook Air running on OS X Mavericks. I am using Maple16.

I created a procedure, which construct two keys. Each of those keys consists of a list containing two elements. That is two primes. So at the end of my procedure I included the following code in order to write my data to a file:

> pkey := fopen(keyFile, WRITE, TEXT);
                      pkey:=1
> writedata(pkey, publicKey);
> fclose(pkey);

The problem is that I can't find the created file "keyFile".

So I tried breaking the problem down. I created a List and wanted to write that list in a textfile in a specific folder:

> L := [1, 2, 3];
> fd := fopen("Users\\****\\Desktop\\fdtest.txt", WRITE, TEXT);
                              fd:=1
> fprintf(fd, "This is a test");
                              14
> fclose(fd);

But this did not work either. It seems like the file fdtest.txt never gets created. This happens in general when I use fopen().

Thank you in advance for your help

Schloemilch

 

 

I have a matrix then I need to plot its columns as curves on one plot.

I'm interested in doing some experimental mathematics using the PSLQ integer relation algorithm.  The only third-party program for doing PSLQ problems I've been able to find is a GNU C++ program with a less-than-user-friendly command-line interface.  I've heard that Maple implements PSLQ and I like the symbolic input and presentation it offers as a CAS, but I can't find any information on which alternative types of Maple 18 make the PSLQ algorithm available.

I am trying to plot several curves with values from matrix columns on one plot.

 

L1 := zip(`[]`, groups, waitArray[ .. , 1]);

L2 := zip(`[]`, groups, waitArray[ .. , 2]);

plot([L1, L2])

plot(L1) and plot(L2) work fine.

But for a joined plot I have an error

 

Error, (in plot) incorrect first argument [Array(1..3, {(1) = [5, HFloat(0.2889190508261187)], (2) = [10, HFloat(0.9017773091123074)], (3) = [20, HFloat(2.4000000155705576)]}), Array(1..3, {(1) = [5, HFloat(0.019538366928174924)], (2) = [10, HFloat(0.06875266075705706)], (3) = [20, HFloat(0.1884304855100058)]})]

f1 := expand((a1*x^2+b1*x+c1)^n);
f2 := a1*x^2+b1*x+c1;

solve([coeff(f1, x, 4) = coeff(f2, x, 4),
coeff(f1, x, 3) = coeff(f2, x, 3),
coeff(f1, x, 2) = coeff(f2, x, 2),
coeff(f1, x, 1) = coeff(f2, x, 1),
coeff(f1, x, 0) = coeff(f2, x, 0)], [a1,b1,c1,d1]);

hi,

i cant solve this 

int(1/1-exp(a*x)*erfc(a*x))

restart;

Vector([a, b]);  <a, b>;  # Identical results

a:=[1, 2]:  b:=[3, 4]:

Vector([a, b]), <a, b>;   # Different results. Why?

 

 

 

I have a vector of lists, and each list is composed of indexed names.  For each list, I would like to assign all the indexed names in the list to the first variable of the list.  Right now, I'm trying to select the entries of the list using the op command and then assign one to the other, and get the following error:

Error, invalid left hand side in assignment

June_29.mw

Thanks!

how to convert decimal number into given decimal number like algebra

for example, convert 191.715 , given a=12.2, b=3.5

how to find this a^2 + b^3

Hello, I am a student typing up my homework assignments with maple, and I am takinng Inferential Statistics.  I can't figure out how to make the bar over a variable, so I can note the average.  It is just a line over a letter.  Kind of when notating a vector without the arrow.  It would be very helpful because I can't figure out how to make that symbol, it is not listed on the symbols list on the left side.

Thanks!

 

hi.i encountered this erroe  [Error, (in dsolve/numeric/bvp/convertsys) unable to convert to an explicit first-order system] with solving set of differential equation.please help me.thanks a lot  

dsys3 := {`1`*h1(theta)+`1`*(diff(h1(theta), theta, theta))+`1`*(diff(h2(theta), theta))+`1`*(diff(h2(theta), theta, theta, theta))+`1`*h3(theta)+`1`*(diff(h3(theta), theta, theta))+`1`*(diff(h1(theta), theta, theta, theta, theta)) = 0, `1`*h2(theta)+`1`*(diff(h2(theta), theta, theta, theta, theta))+`1`*(diff(h2(theta), theta, theta))+`1`*(diff(h1(theta), theta))+`1`*(diff(h1(theta), theta, theta, theta))+`1`*(diff(h3(theta), theta))+`1`*(diff(h3(theta), theta, theta, theta)) = 0, h3(theta)^5*(`1`+ln(h3(theta))^2*`1`+2*ln(h3(theta))*`1`)+(diff(h3(theta), theta, theta))*h3(theta)^4*(`1`+ln(h3(theta))^2*`1`+2*ln(h3(theta))*`1`)+(diff(h3(theta), theta, theta, theta, theta))*h3(theta)^4*(`1`+ln(h3(theta))^2*`1`+2*ln(h3(theta))*`1`)+h1(theta)*h3(theta)^4*(`1`+ln(h3(theta))^2*`1`+2*ln(h3(theta))*`1`)+(diff(h1(theta), theta, theta))*h3(theta)^4*(`1`+ln(h3(theta))^2*`1`+2*ln(h3(theta))*`1`)+(diff(h2(theta), theta))*h3(theta)^4*(`1`+ln(h3(theta))^2*`1`+2*ln(h3(theta))*`1`)+(diff(h2(theta), theta, theta, theta))*h3(theta)^4*(`1`+ln(h3(theta))^2*`1`+2*ln(h3(theta))*`1`)+h3(theta)^4*(`1`+ln(h3(theta))^2*`1`+2*ln(h3(theta))*`1`)+h3(theta)^4*(diff(h2(theta), theta, theta, theta, theta, theta, theta))*(`1`+ln(h3(theta))^2*`1`+2*ln(h3(theta))*`1`)-beta*h3(theta)^3*`1`-chi*ln(h3(theta))^2*`1`/kappa-chi*`1`/kappa-2*chi*ln(h3(theta))*`1`/kappa = 0, h1(0) = 0, h1(1) = 0, h2(0) = 0, h2(1) = 0, h3(0) = 1, h3(1) = 1, ((D@@1)(h1))(0) = 0, ((D@@1)(h1))(1) = 0, ((D@@1)(h2))(0) = 0, ((D@@1)(h2))(1) = 0, ((D@@1)(h3))(0) = 0, ((D@@1)(h3))(1) = 0, ((D@@2)(h3))(0) = 0, ((D@@2)(h3))(1) = 0}; dsol5 := dsolve(dsys3, 'maxmesh' = 600, numeric, output = listprocedure);
%;
Error, (in dsolve/numeric/bvp/convertsys) unable to convert to an explicit first-order system

 

Let be given the complex number z  satisfying condition abs(z+3-2I)=3. I want to find the set of points representing the complex number w, knowing that w - z = 1 +3I. I tried

Restart:
assume(a::real, b::real,x::real, y::real);
z:=x+y*I;
w:=a+b*I;
abs(w-1-3*I+3-2*I)=3;

 

Edit

Restart:
assume(a::real, b::real,x::real, y::real);
Set:=abs(z+3-2*I):
w:=x+y*I;
sol:=solve(w - z =1+3*I,{z});
z1:=subs(sol,Set);
A:=abs(z1);
map(x->x^2,A=3);

I do have some m files and they containing procedures where i am interested in
How can i read those procedures in a m file

Thanks in advance

Hi Maple friends. :)

I would like to graph and solve: 2*sin(2 x)=1 for the interval 0<=x<=360. My textbook gives the answers of x=15, 75, 195 and 225.

But I get an error messages:

plot(2*sin(2*x) = 1, x = 0 .. 360);
Error, invalid input: plot expects its 1st argument, p, to be of type {array, list, rtable, set, algebraic, procedure, And(`module`, appliable)}, but received 2*sin(2*x) = 1

solve(2*sin(2*x) = 1, x = 0 .. 360);
Error, invalid input: too many and/or wrong type of arguments passed to solve; first unused argument is x = 0 .. 360

Any help would be appreciated! Thanks in advance.

 

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