Let a be som expression like
a:=t^2

Now how do I define a function using a.

f:=t->a
doesnt work

Hello there, could someone tell me how to input this differential equation?

d²x/dt² - (3)dx/dt + 2x = 2t -3 

x=2, t=0, dx/dt=4

restart:

Eq1:=x=(phi*(theta[m]-1/x)/theta[m]+(1-phi)/2);

solve({Eq1},x);

x := (1/4)*(phi*theta[m]+theta[m]+sqrt(phi^2*theta[m]^2+2*phi*theta[m]^2-16*phi*theta[m]+theta[m]^2))/theta[m];

Now plotting the first root

p1:=plot(subs(phi=0,x),theta[m]=0..14,color=red):
p2:=plot(subs(phi=0.1,x),theta[m]=0..14,color=green,linestyle=2):
p3:=plot(subs(phi=0.5,x),theta[m]=0..14,color=blue,linestyle=3):
p4:=plot(subs(phi=1,x),theta[m]=0..14,color=black):
display({p1,p2,p3,p4},axes=boxed,view=[0..14,0..1]);

Note: I'm unable to reproduce the following plot. Any idea?

 SA.mw

I am attempting to plot an initial value problem in Maple 18.  I have my equation defined, as well as a general solution and two particular solutions at y(0)=3/4 and y(0)=1/2.  To graph, I entered the command

DEplot(de,y(x),x=-3..3,{[0,1/2],[0,3/4]},dirgrid=[12,12],color=black,linecolor=blue,thickness=2);

but instead of returning a graph, the software gave me the error message

Error, (in DEtools/DEplot/CheckDE) extra unknowns found: sinx

The Maple support site lists this as an unknown error, and as a new user, I'm not sure what to do.  What does this mean?

Hi,

So I have a simple while loop and keep receiving this error and have no idea how to fix it. I don't get why it works for the first few, and then the error starts. Here is my code and output:

Input:

restart;
n:=0:
x:=Pi/3;
m:=0:
total:=0:
while abs(1/2-total) > 10^(-8) do
k:=((-1)^(n/(2))*x^(n))/(n!):
total:= total +k;
evalf(total, 11);
print(%);
n:=+2;
end do:

OUTPUT:
1
- Pi
3
1.
0.45168864437
Error, cannot determine if this expression is true or false: 0 < -50000001/100000000+(1/18)*Pi^2

Why does it think i'm asking if something is greater than 0? Any help??

I'm a calulus 1 student, using Maple to help write my homework assignments. I came across this problem I'm having with Maple 18.

I'm working on explaining analytically where the veriticle asymptotes occur on f(x) = cos*x/(x^2+2*x);

I get all of it done, and at the end I want to insert a plot of this function to finish my disussion.

This is very surprising to see Maple behave this way. What am I doing wrong? Or why is Maple not plotting a simple graph accuratly??

Hello everybody!

My name is Mathew and I am a new member of this forum, and this is my first post, so please be lenient towards me:) I wanted to ask for help since my adventure with Maple 18 was supposed to start yesterday, unfortunately I encountered a problem I couldn't solve myself so far- my Maple 18 does not integrate. At all. It has no problem with differentiating, adding, subtracting and such, unfortunately any type of integral is unsolvable by Maple. I tried typing the easiest functions, such as e^2xdx under the integral, unfortunately it is met with following message:

Error, (in int) wrong number (or type) of arguments: invalid option value passed to indefinite integration: {}.

I understood from several tutorials on the internet that this program should not have any problems with dealing with such form of formulas. What could be wrong? How to make  it work as it is supposed to?

Please help me. As I mentioned in the beginning, I am a new member, so in case I did something wrong or placed this post in wrong category- please forgive me;)

How I can get a list of all label refernces of a worksheet. In fact I want to write a small code which would produce the LaTex output (written to a text file) for my indicated labels. thanx

I am new to Maple. I am working though the manual and in chapter two I tried to get the derivative of ln(x^2+1). I am getting something completely different that the actual derivative. I tried a simple derivatie (the derivative of 2x and get 0). I do not know what I am doing wrong. Any help will be appreciated.

This is a very simple suggestion that weights heavily on my enjoyment of Maple.

I'm not sure if it is only me and my students but it is really tricky to resize a code edit region. Trying to get a hold of the contour in an exercise in patience! Can anyone fix this?

Thanks!

Stéphane

Hi,

  Suppose I would like to use writedata for a series of files, e.g. test1.txt, test2.txt, test3.txt.  

I tried

***

a_min:=1;a_max:=3;
b_min:=1;b_max:=3;
A:=array(a_min..a_max,b_min..b_max);

for i from a_min to a_max do
  for j from b_min to b_max do 
     A[i,j]:=i*j;
  end do;
end do;

for i from 1 to 3 do
  file_name:=`test||i`;
  writedata[APPEND](file_name,A);
end do;

****

Seems "||" inside `` does not work, is there any robust solution for this issue? 

Thank you very much

I want to put the solution obtained from ShowSolution() command of Student[Calculus1] into my LaTeX file. How I can achieve that?

I succeeded in getting latex of ExpandSteps because it was a module, but ShowSolution() is not a module.

I am required to generate a list containing the square of numbers 1 through k where k is an arbitrary int,defined from 1 to n. To do this, I've currently got the following commands:

local k, mylist:=[];

for k from 1 to n do

mylist[k]=sumsquare(k);

end do;

where sumsquare() is a procedure I defined to compute the sum of the squares of 1 through a number passed as an argument

At present this gives me an out of bounds error. 

How can I initialize mylist to be of size n, like in other languages such as C++?

hi

i want to use Direct Search Package for solve system of equation but i have an error:

Error, SolveEquations is not a command in the DirectSearch package.

please help me. code is attached.boltmohasebe.mw

Hi,

  Suppose I have the following code

***

f[1]:=x1^2+x2;
f[2]:=-x2^3+x1-2;

solve({f[1], f[2]}, {x1, x2}):
a,b:= eval([x1, x2], %[1])[]:
a, b;

***

It could work and give me "1 and -1". 

I would like to have a general subroutine, solving f[1]...f[n]. I cannot input  "solve({f[1], f[2],....,f[n]}, {x1, x2}):" just like that. Is ther any way to use "solve" or similar module to handle arbitary number of variables?