Hi everyone--my differential equations course is using Maple; this is my first time using the program and I am a little cofused. 

In a lab component we are told to take the differential equation " dy/dx = sin (x - y) " and substitute in y = ax+b, then determine which coeffecients of a and b should be in order to obtain a solution.

I have made many attemps at this substitution, but am encountering syntax errors no matter what I do:

http://imgur.com/WVQsUQy

I know the general equation would be written in Maple as

>

..which presents no problems for me, format-wise, and generates a nice output.

However, any iteration I've tried with substituting y = ax+ b has resulted in an error like those shown in the linked image above; I'd really appreciate it if someone could explain how I would do the substitution and maybe what I'm doing wrong, syntax-wise.

Thank you for your time!

I'm having trouble with using constrained optimization to solve a problem.

The problem is set up as:

Max: w=x1/2 y1/4

Subject to: K=x+4. K is a constant.

I'm not sure where to start.

Hi all,

I want to solve a cubic equation as is attached here. I solved it in my Maple file which is attached too. But mu result differs from that is showed in the picture. help me please.

Cubic_Eq.mw

map(f, foldl(`*`, 1, a, b));
foldl(`*`, 1, map(f,a), map(f,b));

map(f, foldl(`+`, 0, a, b));
foldl(`+`, 0, map(f,a), map(f,b));

i discover it can auto calculate ring homomorphism, 

if i define a function f below

factor(map(f, foldl(`*`, 1, a, b))+map(f, foldl(`*`, 1, b, c))) = map(f, foldl(`*`, 1, a, c));

how to convert this f into a function with two input parameters?

 from permutation group to permutation group and inverse this mapping?

how to do?

how can I plot the phase portrait of this system?

Sys := {diff(x(t),t) = y(t)-2*(x(t))^2, diff(y(t),t) = -8*(x(t))^3+4*x(t)*y(t)-5*(x(t))^4-(x(t))^5};

Hi

    The following code displays values of the subscripted variables slf[], a positive integer, and a string variable filler[] which is just a set of spaces depending on how big the corresponding value of slf[] s.  This is to make the printout lined up nicely.  

printf("%s%d%s%d%s%d%s%d%s%d%s%d%s%d%s%d%s%d%s%d\n", filler[1],slf[1],filler[2],slf[2],filler[3],slf[3],filler[4],slf[4],filler[5],slf[5],filler[6],slf[6],filler[7],slf[7],filler[8],slf[8],filler[9],slf[9],filler[10],slf[10]);

   This works fine,but thought there might be a better way.  I tried:

printf("%s%d%s%d%s%d%s%d%s%d%s%d%s%d%s%d%s%d%s%d\n",seq(filler[k],slf[k],k=1..10));

but this came up with an error message.  Is there  a way of doing this more efficiently?

thanks,   David 

guys,i computed a tensorial expression by maple but i think i made mistake.

tensorial.mw

separable form should be (x - something in terms of x1,x2,x3,x4)*(x- something in terms of x1,x2,x3,x4)*(x -something in terms of x1,x2,x3,x4 )*(x - something in terms of x1,x2,x3,x4)

factor(f, x);
Error, (in factor) 2nd argument, x, is not a valid algebraic extension

how to factor into separable form?

ferrai := -x1^3*x2*x3*x4-x1^2*x2^2*x3^2-x1^2*x2^2*x4^2-x1^2*x3^2*x4^2-x1*x2^3*x3*x4-x1*x2*x3^3*x4-x1*x2*x3*x4^3-x2^2*x3^2*x4^2+x1^2*x2*x3*y+x1^2*x2*x4*y+x1^2*x3*x4*y+x1*x2^2*x3*y+x1*x2^2*x4*y+x1*x2*x3^2*y+x1*x2*x4^2*y+x1*x3^2*x4*y+x1*x3*x4^2*y+x2^2*x3*x4*y+x2*x3^2*x4*y+x2*x3*x4^2*y-x1*x2*y^2-x1*x3*y^2-x1*x4*y^2-x2*x3*y^2-x2*x4*y^2-x3*x4*y^2+y^3;
coeff(ferrai, y^3);
coeff(ferrai, y^2);
coeff(ferrai, y);
res := simplify(ferrai - coeff(ferrai, y^3)*y^3 - coeff(ferrai, y^2)*y^2 - coeff(ferrai, y)*y);

c2 := -coeff(ferrai, y^2)/coeff(ferrai, y^3);
sys1 := c1*c3 - 4*c4 = coeff(ferrai, y)/coeff(ferrai, y^3);
sys2 := -c3^2-(c1^2)*c4+4*c2*c4 = res/coeff(ferrai, y^3);

diff(lhs(sys1),c1) = diff(rhs(sys1),c1);
diff(lhs(sys1),c3) = diff(rhs(sys1),c3);
diff(lhs(sys1),c4) = diff(rhs(sys1),c4);

diff(lhs(sys2),c1) = diff(rhs(sys2),c1);
diff(lhs(sys2),c3) = diff(rhs(sys2),c3);
diff(lhs(sys2),c4) = diff(rhs(sys2),c4);

c1sol := solve(diff(lhs(sys2),c4) = diff(rhs(sys2),c4), c1)[1];
indets(subs(c1=c1sol,sys1));
indets(subs(c1=c1sol,sys2));
indets([subs(c1 = c1sol, sys1), subs(c1 = c1sol, sys2)]);
result := solve({subs(c1 = c1sol, sys1), subs(c1 = c1sol, sys2)},{c3,c4}, explicit);

c1sol := solve(diff(lhs(sys2),c4) = diff(rhs(sys2),c4), c1)[1];
c2sol := -coeff(ferrai, y^2)/coeff(ferrai, y^3);
c3sol := rhs(result[1][1]);
c4sol := rhs(result[1][2]);
f := x^4-c1sol*x^3+c2sol*x^2-c3sol*x+c4sol;
aa := factor(f);
aa := factor(f,x);

As an exercise, I'm trying to replicate the table shown at the end of section 10.3 (Creating Embedded Components) of the Maple User Manual, the table on page 308 of the PDF, reproduced here:

I create a 6 x 3 table, and merge cells of columns 1 and 2 in each of rows 1, 2, 5 and 6, and proceed to enter the text and components from the Embedded Components example 2 to look as above. In column 3, I merge the cells in rows 2, 3, 4, 5 in order to place the plot component as shown. The new cell seems to be considered as in the same row as its top merged cell, in this case, row 2.

I can't control vertical positioning in the plot cell in column 3. If I select the vertical alignment for the plot cell (which sets the same vertical alignment for all of row 2), to Centre or Bottom or Baseline, the alignment is to the centre or bottom or baseline of row 2, not of the plot cell. So when I paste the plot into the cell it extends up from the Centre or Bottom or Baseline of row 2, to well above the table's top border.

If instead I set the vertical alignment to Top, then the pasted plot fits into the cell since the top of the plot now aligns with the top of row 2. But that can be an annoying restriction. Also, I am no longer allowed to set the vertical alignment in rows 3, 4 or 5 because of the merged cell in column 3.

Maple document tables need to have two improvements:

1. The ability to adjust vertical centring in a single cell (merged or not), instead of just across a row.
2. The ability to resize row height. Currently it looks like document tables only allow resizing column width.

I guess my question is mainly, is there a better way to go about setting up a document table in order to control fairly precisely how it appears? And to get around some of these formatting restrictions?

sqrt(5) gives

sqrt(1+sqrt(5)) gives "You have entered an invalid Maple expression"

sqrt(u) gives

sqrt(1+u); gives "You have entered an invalid Maple expression"

when using the Maple Math icon. How can I get the correct input for the two expressions?

Can Maple simplify these DE's by eliminating the d/dt VL(t) by taking the derrivative of the bottom equation and substituting in the first one? 

Hi, does anyone know how to choose the variables that populate the DAE Variables box when you use "equation extraction"?

I want the result to be in terms of the voltage source and the voltage drop across the capacitor for a RLC circuit.  I want to be able to choose the input-output variables for the final equation.

In this question, I asked for a way to simplify an expression containing radicals. The discussion led us to that as default field for simplicfication is the Complex number system we should use assume or assuming command to simplify the radicals. However, the mothod suggested there seems to not work in this new case that I have. For details please see the attached file. The terms sqrt{u} and sqrt{u-1} should cancel in denominator.

 What Maple Does

Radical.mw

 Remark by Markiyan Hirnyk. The below content is added by the questionner on 08.02.2016 .

What Mathematica Does

I have downloaded the zip file for CalcP7, unzipped it, and can access its commands in a worksheet after issuing the command with(CalcP7), but "No Matches Found" displays when entering the command ?CalcP7. The download included a file named "aplication" (one "p") of type HDB, but Maple15 can't seem to access its contents.

Are CalcP7's help pages displayable? If so, what is necessary to access them?

I have had no trouble downloading the user package DirectSearch and accessing both its commands and its help pages.