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?

hello

I have a system of equation. to solve i using DirectSearch pakage. i think in answer DirectSearch use rounding number but in answer it's second and third digit after the decimal point is important. please help me. bbw.mw

if b and c increase 0.01 and -0.01 it's ok. another main question is why by increasing the intensity answer don't change.

Hi everyone,

I've been having a problem trying to correct this procedure so that it will accept empty tables as well. This is the code I've been messing up with:

6.10.mw

If someone could help me with this, it would be really appreciated.

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 wish to convert:

Sum(x[k],k=1..n)*Sum(y[k],k=1..m) -> Sum(Sum(x[j]*y[k],j=1..n),k=1..m)

Can anybody show me an elegant way to do it?

Gracias

Hello:

I have a simple program to find the intercepts of an equation but I would like to program to ask the user:Would you like the run the program again?  Below is my code:

interceptslope()

all the program stuff

end proc:

Do you want to run the program again? Yes/No

How do I call the program again

Lonnie

Good day everyone, how can one check for the congence of numerical solution of this ODE in maple? See it here 1.mw

Best regards.

Hi,

I recently reinstalled OSX (from Mavericks to Yosemite), and since then, Maple wont solve. Neither in document or worksheet mode. I have never seen the error before, and cannot find any help online.

"

solve(x-8*(1/12) = 0, x)
Error, (in solve) invalid input: hastype expects 2 arguments, but received 1

> solve(x-8*1/12=0,x);
Error, (in solve) invalid input: hastype expects 2 arguments, but received 1

solve({x-8*y = 0, 2*x-4*y = 1}, [x, y])
Error, (in solve) invalid input: hastype expects 2 arguments, but received 1

 "

Restarting maple does nothing.

Anyone know what's wrong? My schools license for older versions of Maple are expired, so haven't tried that.

Thanks a lot.

Can the spacing between gridlines on a plot be modified? i.e., can I have more lines?

I've got the following 

with(plots):
tubeplot([cos(t),sin(t),t], t=0..6*Pi, radius=1/3,
style=patchnogrid, shading=Z, axes=box, orientation=[40,70]);

which gives the plot of a spiral and need to make an animation of a rotating spiral.

I've tried 

animate([cos(t),sin(t),t], t=0..6*Pi,numpoints=200,frames=20,shading=Z,axes=box) but that doesn't work. What am I doing incorrectly?

Hi, Very new to Maple. This is a math assignment, and well I am not exactly sure what is happening. I have had a buddy to help me, but things are not necessarily working. Using Maple17.
This is what I have so far.

de := sin(x)*(diff(y(x), x))+cos(x)*y(x) = Q;
/ d \
sin(x) |--- y(x)| + cos(x) y(x) = Q
\ dx /
dsolve(de);
Q x + _C1
y(x) = ---------
sin(x)
ab := 75; Q := 2-0.1e-1*ab; M := 4+0.1e-1*ab;
75
1.25
4.75
PS := simplify(dsolve({de, y((1/2)*Pi) = M}, y(x)));
-10 x - 38 + 5 Pi
y(x) = - -----------------
8 sin(x)
z := rhs(PS);
-10 x - 38 + 5 Pi
- -----------------
8 sin(x)
N := evalf(subs(x = .4, z));
8.439521805
a := z, x = 0 .. Pi, y = 0 .. 10; b := plots[pointplot]([(1/2)*Pi, M]); c := plots[pointplot]([.4, N]); d := plots[pointplot]([x0, y0]); plots[display]({a, b, c, d});
z, x = 0 .. Pi, y = 0 .. 10
Error, (in plots:-pointplot) points cannot be converted to floating-point values
Error, (in plots:-pointplot) points cannot be converted to floating-point values
Error, (in plots:-pointplot) points cannot be converted to floating-point values
Error, (in plots:-display) expecting plot structures but received: {c, d, z, plots:-pointplot, x = 0 .. Pi, y = 0 .. 10}

The regular plot3d command takes in the range of x and y but if I have been asked to "choose a range of z to get a nice picture" what command can I use apart from implicitplot3d, which in this case doesn't seem appropriate?

I've got the following code:

with(plots):
a:=seq(combinat[fibonacci](k), k=2..10);
for i from 1 to 5 do
#with(plots):
multiple(plot,[sin(a[i]*x),x=-2..2,-2..2,color="Red",legend=typeset("Curve1:",sin(a[i]*x))],[sin(a[i+1]*x),x=-2..2,-2..2,color="Green",legend=typeset("Curve2:",sin(a[i+1]*x))],title=typeset("Lissajous",i));
end do;

that plots the sine functions of consecutive fibonacci numbers pairwise. Now, if I had to use the display command to plot these pairs together, how would I be able to do so?

I wish to recalculate the document from the beginning (or from the last restart) without having to select everything and push the "!" button.

Hello everybody,

I guess my problem is a very little one, but I don't have any idea how to solve the following equation:

The equation is defined as follows:

gl1 := a = (arctan(b^2/(z*sqrt(b^2+b^2+z^2)))+b^2*z*(1/(z^2+b^2)+1/(z^2+b^2))/sqrt(b^2+b^2+z^2))/(2*pi);
                                       
z := solve(gl1, z);

Warning, solutions may have been lost

Does anybody of you have an idea how to solve this problem?

Thanks so much in advance!