Hello together,

After doing some Maple work i got this Equation of Motion:

I'm not sure how I am able to solve this differential equation.

I am able to do it by Seperation of the variables by hand, but Maple should be able too?

Thanks for the help, everything is appreciated!

When I plot someting in Maple17, it appears in a small square window that's horizontally centered.  I want to be able to create plots that appear larger.  There's plently of space on the screen for plots to be much larger.

Yes, I know I can grab the corner of a plot and drag it to make it bigger.  That's not what I want (that takes time, and it's tricky to maintain the aspect ratio).  I want the plot to appear large when I execute the plotting command.

I've searched for answers both on Google and mapleprimes, and come up empty.

If I have the following system of first order diff eq's:

x'(t)=2x(t)+3y(t)

y(t)=-3x(t)-2y(t)

then can I consider the coefficient matrix A=<<2,-3>,<3,-2>> and compute the eigenvalues of A and infer as follows:

if the eigenvalues are of the same sign- eq point is a node

if they are of opposite signs- eq point is a saddle

if they are pure imaginary- eq point is a center

if they are complex conjugates- eq. point is a spiral

I've been given these conditions but my text says for a linear system of the form x'=Ax, the eigenvalues of A can be used to identify the nature of the eq. point. I am confused as to whether this applies to the given system as well; I have obtained 5 different trajectories and drawn the phase diagram for the system

I have the following :

with(powseries):
difeq:=diff(y(x),x,x)+x*y=0;
icval:=y(0)=1,D(y)(0)=0;
pow_soln:=powsolve({difeq,icval});
tpsform(pow_soln,x,30);
pow_soln(_k);

for which the  transformed power series

is : 1 -(1/6)y*(x^3)

and pow_soln(_k) returns 0. What does this mean?

What is the best way to solve for the simple equation X^2+y^2=1[m]^2 symbolically for either x or y? I actually have a huge list of equations and want to solve the group but my problem boils down to the issue here where I get two possible solutions though using the assumption one is clearly negative and the assumption used should exclude negative results (see attempt below). Also solve doesn't seem to work with units either...  any ideas? Can I give the variables units in a meaningful way?

--------------------------------------------------------------------------------------------------------------------------

restart;

with(RealDomain);
f := x^2+y^2 = 1;

                            x^2+y^2 = 1

assume(y > 0)

a := y > 0

y1 = solve(f, y, useassumptions = true)

                          y1 = (sqrt(-x^2+1), -sqrt(-x^2+1))

y2 = solve({a, f}, y)

                          y2 = ({y = sqrt(-x^2+1)}, {y = -sqrt(-x^2+1)})

-------------------------------------------------------------------------------------------

Why is y = -sqrt(-x^2+1) a solution?

Also, how do I use units when trying to solve 

-------------------------------------------------------------------------------------------

restart;
f := x^2+y^2 = Unit('m')^2;
                           x^2+y^2 = Unit('m')^2

assume(x > 0);
assume(y > 0);
d = solve(f, y, useassumptions = true);

Error, (in Units:-Standard:-+) the units `m^2` and `1` have incompatible dimensions

---------------------------------------------------------------------------------------------

THANKS!

My assignment is to plot 3 graphs when u0=65.70 and 95 and I thought I did my code properly but now I am getting weird errors

a0:=80;
a1:=-5;
b1:=-5*(3)^0.5;
w:=Pi/12;
k:=0.2;
u0:=65;

t=0:0.001:100;
c0=u0-a0-(k^2*a1-k*w*b1)/(k^2+w^2);
c1=(k^2*a1-k*w*b1)/(k^2+w^2);
d1=(k*w*a1+k^2*b1)/(k^2+w^2);
u=a0+c0*exp(-k*t)+c1*cos(w*t)+d1*sin(w*t);
plot(t,u,'r');

I am getting an error here that says Error, (in plot) unexpected options: [65., r] and I don't know how to fix this


legend('u(0)=65');

hold on;
u0=70;
c0=u0-a0-(k^2*a1-k*w*b1)/(k^2+w^2);
c1=(k^2*a1-k*w*b1)/(k^2+w^2);
d1=(k*w*a1+k^2*b1)/(k^2+w^2);
u=a0+c0*exp(-k*t)+c1*cos(w*t)+d1*sin(w*t);
plot(t,u,'-');

I am also getting an error with the '-' portion of my plot "Error, invalid uneval"

legend('u(0)=70');

hold on;
u0=95;
c0=u0-a0-(k^2*a1-k*w*b1)/(k^2+w^2);
c1=(k^2*a1-k*w*b1)/(k^2+w^2);
d1=(k*w*a1+k^2*b1)/(k^2+w^2);
u=a0+c0*exp(-k*t)+c1*cos(w*t)+d1*sin(w*t);
plot(t,u,'g');

I am getting an error yet again with my plot and this time it is "Warning, expecting only range variable u in expression t to be plotted but found name t"


legend('u(0)=90');

I am new to maple, having recently made the switch from mathCAD, and I am having problems getting the basics to do what I think they ought to be doing.

I am trying to get maple to go step by step through a derivation of a formula. In one line I define a variable

U4 := expression

In the next line I will call the same variable and take the derivative of it. Sometimes it works and sometimes it evaluates to zero when it should not. I can't seem to pin down a pattern of when it does and does not work. I will change something that is not working, and then change it back, and it will work. Am i assigning my variables inconsistently? 

I took a screencapture of the worksheet in question. Thanks in advance for the help.

****** My question *****

for k from 0 to n do    # n is any integer.

func := f(x):             # func is any funciton of x.

D := diff(func, x$k);   # The maple don't allow to uses k but I want to diff k-th order in each k-loop.

end do;                    # How to diff func for k-th times in each k-loop.

Hello guys,

I am stuck with the following code. I cannot get a solution. Mapple doesn't even run. Please help, I am in urgent need on help!!!

Compared to Maple on Windows, how do ppl like Maple on Macs ?

Any comments ??

Thanks, cheers !

(

I'm trying to solve a system of four pdes and I know that the Newton method won't converge.

Are there other numerical methods that I can use?

Any help would be greatly appreciated!

Thanks,

Eve

Hi,

I'm an industrial engineering student who's running into problems with solving a simple system of non-linear equations.

Why do I get this error when issuing the solve command? I'm pretty sure I'm only passing two lists into the function?

Thanks a lot in advance,

Joshua

Hi!

Is there any way to remove the empty space that comes under images when printing the project, while using document mode?

Regards

Nicolai

Please fix the MapleCloud service. Is no longer working. E uploaded jobs and are not shown. Fix it please.

I have a matrix A for which the basis of the left null space using NullSpace() is the empty set {}  while the column space is {e1,e2,e3}. By definition, we need every vector in col space . every vector in basis of left null space =0 but how would I show that in this case? Can I determine another basis for the left null space?