MaplePrimes - Questions and Posts tagged with equations

Non-autonomous system of DE to autonomous one

johnnyV — Mon, 17 Jun 2013 18:46:32 Z

Hi,

I'm searching for the third differential equation that will transform the following two equations non-autonomous system into a three equations autonomous one:

diff(x(t),t)=-x(t)+2*(m*t+n)*y(t)-2*k*(m*t+n)²

diff(y(t),t)=-y(t)+k*m-(m*t+n)*((x(t)/2)-1)

diff(z(t),t)= ...

Regards,

Johnny

Problems in Solving a complex Equation

tevez32 — Thu, 13 Jun 2013 15:08:19 Z

Hello, im a current user of Maple 16, i have a problem in finding a minimum of equation ( equation of a external work equating the internal energy dissipation) f= E-W ( im studying a slope stability with limit analysis)

the equation is:

How to solve a set of linear and nolinear equations

pawarabhijit7 — Sat, 08 Jun 2013 08:03:49 Z

I have total nine equations,out of which some are linear and some of them are nonlinear.I am a new user of maple.The nine equations are

c2+vc = .34,

c2+c3 = .519,

t8+c3-c4-vc = .132,

t1+t5-c2+0.0435=0,

t1-t2-c2+c3-1.334*vc = 0,

t2+t6-c3-c4+0.0435+1.334*vc=0,

-112.5*t1+112.5*t5+300*c2^2+1000*vc = 38.25,

112.5*t1-112.5*t2-300*c2^2+300*c3-300*c3^2-2000*vc+23.4 = 0,

-112.8*t8+112.5*t2-112.5*t6+300*c4^2-300*c3+300*c3^2+1000*vc+14.85 = 0

differential equation solutions

Ratch — Fri, 03 May 2013 21:38:42 Z

Many times when I use dsolve to find the solution of an equation like x-y/y' = y , I get a term involving the LambertW function. However, the equation has homogeneous coefficients for dx and dy, so it can easily be solved by substituting y=u*x and separating the variables. The closed form solution of the above is x+y*ln(y)+c*y = 0 , but I cannot get that answer from Maple. Is there...

Name of equation with spaces

andmail — Sat, 20 Apr 2013 11:34:34 Z

Hello!

It seems there's some problems with spaces in the name of equation

As you can see the 'SOLVE' command can't substitute variable 'b' in my example, if 'b' variable wasn't defined BEFORE the equation with spaces in its name....

How do I solve the following system in Maple?

cloocloo — Wed, 27 Mar 2013 11:15:08 Z

Hi everybody. Firstly, i apologize for my poor level of english. I am a new maple user and i want to solve the following system, but I face some difficulties. I go through forum, FAQ, courses notes on the net and so on but I don't find the solution.

I first define the folowing equations:

Animation spatial lever mechanism.

one_man — Mon, 18 Mar 2013 19:43:09 Z

Animation spatial lever mechanism on the basis of one of the sets of solutions of systems of polynomial equations. The Draghilev method. MECAN123.mw

[URL=http://hostingkartinok.com][IMG]http://s5.hostingkartinok.com/uploads/images/2013/03/d221bb8e1764dc92d63213aac4a0429a.gif[/IMG][/URL]

Solving system of polynomial equations

Stavros — Sun, 17 Mar 2013 18:41:49 Z

Hi! I have a matrix A where the entries

satisfy the conditions in eq1. I set A equal

to the general

4x4 matrix X and convert to a set so that I can

solve the system of equations for the variables

in A (i.e. solve for a,b,c,d, s,t,r,l). However,

in my program below, I get "res:= "

when the program finishes. Why isn't it

giving me any output? Thanks!

Assign name to one of multiple results

9colai — Thu, 14 Mar 2013 13:22:27 Z

Hi!

I need to assign a name to a result calculated from a system of equations. In this case, i've got 2 equations and 2 solutions. I want to assign a name to the each of the solutions.

solve({-a+4*b = 0, 2*a+7*b = 2}, {a, b})

{a = 8/15, b = 2/15}

How do i assign a name for a and another for b?

How does one solve integral equations in Maple?

George B — Thu, 14 Mar 2013 05:58:26 Z

How does one solve integral equations in Maple?

How does the program terminate after exactly 1 solution has been found?

Stavros — Wed, 13 Mar 2013 15:32:54 Z

Hi!

In the program below, all solutions are found for the equation S.R=T subject to

the constraints given by eq1 and eq2. I've tried it for a

few different choices of T and there's usually 80+ solutions.

I want to try more complicated choices of T (for example,

I want the matrix T to have every entry a distinct prime number).

But then the program crashes. I assume the equations get complicated

or there...

Plotting with a constant

Lalalaika — Thu, 07 Mar 2013 16:29:50 Z

Hello, I have a problem with plotting graphs with a constant.. I have one system of equations and one another equation:

dx/dt=x(t)

dy/dt=ky(t)

and

|y|=C|x|^k

I need to compare theit curves.

k and C are constants. I thought it is alright if I would remove constants, BUT there is one in the power, so I have no idea what to do..

I just tried to plot the system, but it doesn't work either:

Set of expressions to matrix

sebastianus — Sun, 24 Feb 2013 16:05:38 Z

How to interpolate roots for a curve expressed in numerical arrays

mapleq2013 — Fri, 15 Feb 2013 21:40:09 Z

I'm solving a system of ordinary differential equations numerically, I used the dsolve(system,numeric) to do it. I have also plotted the solutions. Now I want to know where does this solution cross zero and use this value for later computations, is there a way to do it?

This question is, as I think, equivalent to how to find the roots for a curve expressed in numerical arrays.

Thank you!

Solving system of differential equations with bound on solutions

mapleq2013 — Thu, 14 Feb 2013 21:43:40 Z

I know how to solve system of differential equations numerically, but now I want to know how to set a bound on the solutions.

For example, if my system of DE is like this: dx/dt = x+y dy/dt = x-y , solve x and y in t.

I can solve this without any restriction on x and y, now I need to know how to bound x and y, e.g. x can only fall in the interval [0,1]

Thank you very much!