r := sqrt(x^2+y^2+z^2);
divE := diff(e*x/(4*Pi*r^3), x)+diff(e*x/(4*Pi*r^3), y)+diff(e*x/(4*Pi*r^3),z);
simplify(divE);

of a square matrix having its entries 1,2,...16? See http://oeis.org/A085000 for info.

I want to plot this contour 4x^2+9y^2=160  onto the same f(x,y)=4x^2+9y^2.  The error I keep getting is

Error, (in plot3d) first argument must be either in standard or parametric form

Thanks

I can;t seem to get DSOLVE working.  Will some kindly soul please send me a complete example, starting with an f(x) & clearly documented?   Many thanks.

AB

Suppose I have a file, test.txt, which the content is

2
2 0.0 0.0 0.0
1 0.0 0.0 1.6

I would like to save 

Z:=2;

C[1,1]:=2;C[2,1]:=0.0;C[3,1]:=0.0;C[4,1]:=0.0;

C[1,2]:=1;C[2,2]:=0.0;C[3,2]:=0.0;C[4,2]:=1.6;

However, if I use readdata("...",4), seems it do not work.

Is there any flexible command in maple can readfile with different column? Thank you very much!

I am having difficulty with the contourplot3d.  When I hit enter it comes back with a blank plot.  Either Im doing somthing wrong or my machine can't handle it.

restart;

with(plots);

Eq1 := diff(f(eta), eta, eta, eta)+f(eta)*(diff(f(eta), eta, eta))-(diff(f(eta), eta))^2-M^2*(diff(f(eta), eta))+B(f(eta)*(diff(f(eta), eta, eta))*(diff(f(eta), eta))-f(eta)^2*(diff(f(eta), eta, eta, eta))) = 0;

Eq2 := (diff(theta(eta), eta, eta))/Pr+f(eta)*(diff(theta(eta), eta))-2*(diff(f(eta), eta))*theta(eta) = 0;

Pr := 1

M := 1

S := 0

epsilon := 1

blt := 10

bcs1 := f(0) = S, (D(f))(0) = epsilon, (D(f))(blt) = 0;

bcs2 := theta(0) = 1, theta(blt) = 0;

L := [0, .2, .4, .6, .8, 1.2];

for k to 6 do R := dsolve(eval({Eq1, Eq2, bcs1, bcs2}, B = L[k]), [f(eta), theta(eta)], numeric, output = listprocedure); X1 || k := rhs(R[3]); X2 || k := rhs(R[4]); Y1 || k := rhs(R[5]); Y2 || k := -rhs(R[6]) end do:

print([(X2 || (1 .. 6))(0)])

Consider the equation

eqn1:=5^(2*abs(y-1)+2) = (1/15625)*625^abs(y-1);

and note that

eval( eqn1, y=-3);
eval( eqn1, y=5);

both return valid solutions. So why does

testeq(eqn1);

throw a numeric exception.

Given the manual description of testeq(), I would expect it to return either true or FAIL - but not a numeric exceprion!!!!

Any ideas?

Hi, is it possible to instantly start the display of plot animations after they are generated in maple? I searched for answers in the documentation and on the internet but couldn't find a solution. I would like to skip the step of manually clicking the plot and the "play animation" button.

Hi,

  Suppose I have a file, 1.mw, which includes a subroutine

aver:=proc(a,b)

  local res;
  res:=(a+b)/2;

  return res;

end proc:

   Now I am writing another file, 2.mw. I would like to load the subroutine, aver, in 1.mw. How shall I write in 2.mw to use that subroutine in 1.mw?

Thank you very much

PS,
PiFast43 is freely available at,

http://numbers.computation.free.fr/Constants/PiProgram/pifast.html

i dont know what`s wrong with it help me guys

Hello everyone,

I want to inseret a text arrow in the graph obtained by plot command to show increasing or decreasing trends of the graph, but I could not find any option to insert the textarrow or textbox in the graph. 

Thanks in advance.

Dear's, I am facing some problem to find the particular solution please find the attachment.

Help-1.mw

PhD (Scholar)
Department of Mathematics