Hi,

When I show the context menu on maple 18 (CTRL click on mac or right click with a mouse) on an equation the system doesn't show the tutor or series options as written in the example I use.   (after having loaded the multivariate calculus as asked)

Is that an issue in my installation ?  Where do I have to place the cursor ?  Is the multivariate calculus module well loaded ?

Thanks for your help

Stéphane

Dear friends,

I would like to know the agorithm of isovle for solving 2 order equations for more than 3 variables.

I see that not all the solutions are shown for example for:

x^2+y^2=z^2+t^2

 Could you please help me with this?

hi,

I have bought maple18 student edition. I want to learn GPU programming through Maple. Please suggest how to do this. I have a notebook with i7 processor and NVIDIA geforce 750m graphics. I want to solve system of algebraic equations, integral equations etc in parallel using GPUs.

thanks

I am trying to simplify sums of a few LaguerreL polinomials of different n using the identities in the function advisor such as recurrsion relations. How does one go about in using the FunctionAdvisor identities when trying to simplify expressions containing orthogonal polynomials? 

I want to generate all 4x4 matrices of rank-1 over the field with two elements, F_2. I don't want to use actual arrays though, I just want to use symbols representing the unit matrices. So for example Eij represents the 4x4 matrix with a 1 in row i & column j, and 0's elsewhere. 

We have 16 unit matrices: E11, E12, ..., E14, ... E41, E42, E43, E44. Then we have to look at all possible linear combinations that result in a rank-1 matrix. So for example: E11+E12,  E11+E21,  E11+E12+E13,  E33+E43, etc. The total number of rank-1 4x4 matrices over F_2 is 225. How can I find all of these quickly?

Hi number of officials,

As I enter the command defined 'int' I get an error message.

What can I do. Can you help me.

Commands Entered:

int(x^2+3*x, x);

ansvers:

Error, (in int) wrong number (or type) of arguments: invalid option value passed to indefinite integration: {}

I'm wondering why the fit routine gives weird results, when telling him to fit

with(Statistics):

X:=Vector[column](3, {1 = 616.3096, 2 = 616.3248, 3 = 616.3342}, datatype = sfloat, storage = rectangular, order = Fortran_order, shape = []);

Y:=Vector[column](3, {1 = 99590., 2 = 127564., 3 = 144223.}, datatype = sfloat, storage = rectangular, order = Fortran_order, shape = []);

g:=Fit(a+b*x+c*x^2,X,Y,x)

It's telling me: Warning, model is not of full rank

If I calculate the coefficients the direct way (well the fit should be exact,because we only have 3 values and 3 parameters) I get:

M:=Matrix(3, 3, {(1, 1) = 1, (1, 2) = 616.3096, (1, 3) = 379837.52305216, (2, 1) = 1, (2, 2) = 616.3248, (2, 3) = 379856.25909504, (3, 1) = 1, (3, 2) = 616.3342, (3, 3) = 379867.84608964}, datatype = anything, storage = rectangular, order = Fortran_order, shape = []);
V:=Vector[column](3, {1 = 99590, 2 = 127564, 3 = 144223}, datatype = anything, storage = rectangular, order = Fortran_order, shape = []);
with(LinearAlgebra):
C:=MatrixVectorMultiply(M^-1,V)

Hi there

I'm trying to isolate (y1-3)²+(x1-1)² in the equation 25(y1-3)²+200+100(x1-1)²=0.

I have tried isolate and solve, but solve coplains about solving for expressions (but when inputting i:=(x1,y1)->(y1-3)²+(x1-1)² it still doesn't work), and isolate can only isolate either (y1-3)² or (x1-1)² . Not both.

How can I do this with as few lines as possible?

Thanks

- Alex

Use the Maple command DEplot to draw a direction field for the equation

make sure it at least covers the area −1 ≤ x ≤ 1,
−1 ≤ y ≤ 1

the equation is dy/dx+4y^3 −3y = 0.

then I have :

y(x):=dy/(dx)+4*y^(3)-3*y=0

with(DEtools); DEplot(y(x), x = -1 .. .1, y = -1 .. .1);

Error, (in DEtools/DEplot) vars must be declared as a list, e.g. [x(t),y(t),...]

so how can I change the command to make it work..

Hello friends,

I want to derive the function of a curve. It's easy in for example "xyExtract" but I don't know how to do it in maple. please help. thank you all.

Hi, I'm new to Maple and was trying to use it to solve 3 equations with 3 unknowns, in terms of another 2 parameters. This is what I put in, and the error that came up:

solve({(1-x)/(1+b) = b*y, (1-y)(1-a)/(-a*b+1) = b*z, (1-z)(1-b)/(-a*b+1) = a*x}, {x, y, z}); 

Error, (in SolveTools:-LinearSolvers:-Algebraic) unable to compute coeff

I want to solve the equations to get x,y,z in terms of a,b but I don't understand the error coming up - have I done something wrong or is it because not all the variables appear in all of the equations? As there are 3 equations and 3 unknowns there is a solution, but I want to check the answer I found on paper with something (the algebra got a bit messy!)

Any help greatly appreciated! :)

I am trying to simplify equation 18 using equations 8 and 9. It should look a little like equation 21, but instead I get the results in equations 19 and 20.  I tried using different substituions, but algsubs gets the closest answer. A few terms are going to zero after the substitution.

When I substitute Z(X) then Zbar(X) terms vanish, and visa versa.

Download Deriving_the_Kerr_Metric.mw

Hi,

I'm trying to create interactive plots by using Explore to help demonstrate the effects parameters have on functions. I created one successfully to illustrate shifts and stretches of a polynomial:

transform(A,B,X,H,P,K):=Explore(plot(a*(b*x+h)^(p)+k,x=X),parameters=[a=A, b= B,h=H,p=P,k=K],placement=right)

However when I try to do the same with a solved ODE it returns an error message:

Explore(plot(1/(-p*x+x+1)^(1/(p-1)), x = -5 .. 5), parameters = [p = -20 .. 20], placement = right);

Executing this gives the error message: 

Warning, expecting only range variable x in expression 1/((-p*x+x+1)^(1/(p-1))) to be plotted but found name p
INTERFACE_PLOT(AXESLABELS(x, ""),

VIEW(-5. .. 5., DEFAULT, _ATTRIBUTE("source" = "mathdefault"))),

parameters = [p = -20 .. 20], placement = right

I'm not sure why it is having difficulty dealing with "p" when it had no difficulty with the first. Any help would be appreciated!

Consider the problem of a hard-hit baseball. The air-friction drag on a baseball is approximately given by the following formula

and subsequent differential equations : 

F:=-((C_d)*rho*Pi*(r)^2*v*v)/2;
m:=0.145;
v0:=65;
g:=9.81;
v_x:=diff(x(t),t);
v_y:=diff(y(t),t);
d2v_x:=-((C_d)*rho*Pi*(r^2)*(v_x)*sqrt((v_x)^2 +(v_y)^2))/(2*m);
d2v_y:=-((C_d)*rho*Pi*(r^2)*(v_y)*sqrt((v_x)^2 +(v_y)^2))/(2*m)-g;

where

C[d] is the drag coefficient (about 0.35 for a baseball)

•
rho[air] is the density of air (about 1.2 kg/
3m
)
•
r is the radius of the ball (about 0.037 m)

v is the vector velocity of the ball

Then if given that : 

Power hitters in baseball say they would much rather play in Coors Field in Denver than in sea-level stadiums because it is so much easier to hit home runs. The air pressure in Denver is about 10% lower than it is at sea level. The field dimensions at Coors Field are:

Left Field - 347 feet (106 m)
Left-Center - 390 feet (119 m)
Center Field - 415 feet (126 m)
Right-Center - 375 feet (114 m)
Right Field - 350 feet (107 m)

 1. Overlay two plots: one at sea level and one in Denver to show why power hitters prefer Coors field.

2. Find the initial magnitude of velocity, v0

needed to hit a home run to Right-Center, where v_x(0)=v0/sqrt(2) and v_y(0)=v0/sqrt(2)

I don't quite understand how to use the field dimensions for both 1 and 2 and am pretty clueless as to how to approach this question using the ordinary differential equations mentioned above.

Hey guys, I'm new to the forum, so please tell if I need to set up the question in a different way :) I've tried to find an answer for this, but have struggled since our learning book is in danish, so the used terms may not be technically correct,

Anyways, how do you solve this problem in maple? 

Find the complete real solution for the differential equation system:

For the homogenous part I've found. (Is this correct?)

  , c1,c2 € R

I've tried to find an answer for the inhomogenous part but I get a really complicated result, so I doubt it's correct.

Thanks for the help :)

-Alex