Hey

I'm trying to solve this trigonometric equation:

e := 4·cos(t)+2·cos(2·t)=0. In the interval 0..2·Pi

However when i try: 

solve([e, 0 <= t <= 2 Pi], t, AllSolutions, explicit)

I won't give my a straight answer.

I have also given Student:-Calculus1:-Roots a try:

Student:-Calculus1:-Roots(e, t=0..2·Pi)

But it will only give me an answer when i use the numeric...

How to do this with Maple? Is it possible?

http://www.mapleprimes.com/ViewTemp.ashx?f=5794_1319135560/poissonHRI-1.jpg

Gracias

Hello, I'm trying to solve a very long system of equations, I've used PolynomialSystem and works, but it does not give me all of the solutions of the system. Im trying to do the solve comand, but after a few hours the mserver crasher and it needs to close, without having an output.

I woul really appreciate if anyone has a solution for this, I need to solve this and I'm getting stuck with this.

I'm attaching my worksheet  

Hi all,

 i have a problem with the equation generation in MapleSim, when using spring/damper elements in a Multibody-System. As an example, I've created a model of a mass-spring-damper system:

Hello everyone.

Now, I am studying nonlinear fitting method through help file of maple. Unfortunately, I'm not getting good fit using NonliearFit. The following is my psocedure:

> restart;
> with(Statistics);
> y := 1/(3.6+2.3*x)+17.6*exp(-0.2*x);
> fy := unapply(y, x);
> for x to 10 do fy(x) end do;
14.5791527795
11.9195840297
9.75432289049
7.98631476846
6.54090333018
5.35848939402
4.39086798669

Hi, I am very new to Maple and i was using Maple with a code that was running well when suddenly the rand() function that i use started to fail. and i get the error:

> rand();

Error, empty number

also i get many aditional errors in some sentences where i am addressed to some '?' simbols which are supposed to be in my sentendes.

has anyone gone trhough that? any help will be appreciated.

josep

I'm trying to do a least square estimation

with(plots);

q := array([892., 1012., 1060., 987., 680., 739., 809., 1275., 946., 874., 720., 1096.]);

p := array([1.23, 1.15, 1.10, 1.20, 1.35, 1.25, 1.28, .99, 1.22, 1.25, 1.30, 1.05])

lnx := array([seq([ln(p[t])], t = 1 .. 12)]);

lny := array([seq([ln(p[t])], t = 1 .. 12)]);

pointplot({seq([ln(p[t]), ln(q[t])], t = 1 .. 12)}, symbol = circle, axesfont = [TIMES, 14], labels = [x = ln(p), y = ln(q)])

Hi all! I have a list of data. I can use pointplot to plot them. Now, whatshould I do if I want to connect (join) these points toghether like an ellipse or rectangle or others form? For example:

S := [[1,1], [3,1], [4,2], [3,3], [2,3], [1,2]];

thanks  

Hi,

Can i use method=laplace to solve an ode with no initial condition?

ode := diff(phi2(x),`$`(x,2))-Omega0*diff(phi2(x),x)-k*R1*E1/C*sigma*phi2(x)-l^2*phi2(x)+2*R*k/C*N2*exp(Omega0*(x-1))*cosh(l*(x-1))*l*C2/exp(-l) = 0;

bcs:=phi2(1)=0,phi2(S0)=-N4*Phi;

sol := dsolve({ode, bcs}, phi2(x), method=laplace);

Thanks

Good night.

I have a problem with this error "Error, (in unknown) invalid input: `dsolve/numeric/lexorder` expects its 2nd argument, b, to be of type {indexed, name, numeric}, but received cos(t) "

help me please

final-robot-circul.mw

Hey,

I have one function that is consisted of several matrices.. The function is,

R := log(determinant(MCOV))+trace(multiply(SCOV, inverse(MCOV)))-log(det(SCOV))-2+Transpose(SM-TAU-multiply(L,K))&*inverse(MCOV)&*(SM-TAU-multiply (L, K));

where MCOV, SCOV, SM,TAU, L, K are all matrics. In a MCOV and L, there are symbols also..

I have tried to get...

Dear Mapleprimes,

I have a problem with the sum command. I'm differentiating wrt. a value q[i] in a sum. I have the following:

diff(sum((1/2)q[i], i=1..n),q[i]);

This returns:

n(1/2)

but I'm differentiating wrt. q[i] not the whole sum. Any ideas?

Thanks very much.

Christian

Hi, I have 2 sets of data:

P := array([1.23, 1.15, 1.10, 1.20, 1.35, 1.25, 1.28, .99, 1.22, 1.25, 1.30, 1.05]);

Q := array([892, 1012, 1060, 987, 680, 739, 809, 1275, 946, 874, 720, 1096]);

p=P(t), q=Q(t) i.e. both p & q are a function of parameter t  t=1..12

2 functions: 

x=ln(p)

y=ln(q)

I'm trying to display x against y , ie x=ln(p) on the horizontal axis, y=ln(q) on the vertical

Dear Mapleprimes,

I'm trying to add a sequence of numbers using the add command. It appears that it can only add up to a specific number. The following works:

add(2*i, i=1..5)

gives 30.

But it is not possible to do:

add(2*i, i=1..n)

such that n is a parameter.

Does anyone know how to add a finite series of values where n is unknown?

Is there a way to change the default settings for ArrayTools[RandomArray](distribution= )  ?

There are two distribution values available uniform, which is on the unit interval and normal which draws from a normal distribution on the unit interval. 

Can we modify those settings?  Such that using distribution=uniform (or normal) is forced to some user setting outside the unit interval?