## How do I write this differential equation (Newtons...

Hi all, I would be most grateful if I could get some help with solving the tasks below using Maple.

Given the function: mx''(t)+cx'(t)+kx(t)= F_y(t)

1. Rewrite the equation above to a system of 1. order differential equations, by defining the two variables x_1(t) = x(t) and x_2(t)=x'(t) (Hint what is x'(t)?) This gives the first differential equation in the system. What is x_2'(t)?

2. Write the equations as a linear system when the outer force F_y(t) is the influence and the position x_1(t) is the answer, in other words give the system matrix A and the vectors b and r.

3. I'm given the constants m = 5kg, c = 3Ns/m and k = 20 N/m and I'm trying to find the transfer function of the system.

4. Give the systems transfer function H(s) and draw the graphs for the amplitude and phase characteristic.

Thank you!

## Plotting functions with units...

Hi there

I'm an old user of Maple, but I've never been able to plot functions with unit. You can see my latest attempt down below

```b := 120*Unit('mm');
h := 200*Unit('mm');
V := 8*Unit('kN');

I__x := (1/12)*b*h^3

Q(x):=(1/2)*((1/4)*h^2-(100*Unit('mm')-x)^2)*b
tau(x):=V*Q(x)/(I__x*b)

plot(Q(x(Unit('mm')), units), x = 0*Unit('mm') .. 100*Unit('mm'))
```

Plot_function_with_units.mw

If anyone is able to help me with this problem, I would greatly appreciate it.

## Warning, solutions may have been lost....

Hello everyone!

I'm having some problem with this equation:

solve(0.1 = 23.714*(-0.93205)^2/(20.3+61.4*.884^x), x)

I'm trying to solve for x, but i keeps saying "Warning, solutions may have been lost."

Any ideas?

## how do i solve a nonlinear Schrodinger in maple?...

hye, can someone help me to solve nonlinear schrodinger equation using maple? i attach with document

solution_nonlinear.pdf

## Need Help: Implicit Differentiation Problem...

Hi Maple Expert,

c*(r-1)*exp(x*beta)/((1+varphi*exp(x*beta))*(-varphi*exp(x*beta)*r+varphi*exp(x*beta)+1))

c = exp(exp(x*beta)*(r-1)/(1+varphi*exp(x*beta)))

with

ln(r) = varphi*exp(x*beta)*(r-1)/(1+varphi*exp(x*beta))-1

Regards,

Sarni

## Maple displays incorrect float....

Maple gives me the incorrect answer to the hundredth place. (arithmetic.mw)

>15000*(1+.06/365)^(10*365)
>                        27330.47804

I tried using an exact fraction 15000*(1+(6/100)/365)^(10*365) as well.

## riemann curvature tensor maple and also need to ...

i) D(X,Y) , D(X,Z) ,D(Y,Z) COVARİANT DERİVATİVE ?

İİ) [X,Y] LİE OPERATOR ?

İİİ) R(X,Y)Z = D DZ - DDZ - D[X,Y] Z

## How to use pdsolve?...

This may be a stupid question, but I am having elementary trouble with pdsolve.

I have the following pde system:

PDE:=[diff(f(x,xp),x)=-(1/2)*(L*xp+2*x)*kl,diff(f(x,xp),xp)=-(1/4)*kl*L*(L*xp+2*x)];

Trying to solve it:

pdsolve(PDE)

I get this error message:

Error, (in pdsolve/sys) too many arguments; some or all of the following are wrong: [{f(x, xp)}, handlenonrationalfunctionsofdependentvariables = false]

I don't understand any of this; can someone enlighten me?

TIA

M.D.

pde.mw

## Is there any Maple code for the "domain coloring" ...

Is there any Maple code that allows to view a complex function using the "domain coloring" technique?

This technique is described for example in Wikypedia: https://en.wikipedia.org/wiki/Domain_coloring

## compute linear schrodinger equation...

how to compute example 1 of linear schrodinger equation?

[Edit: uploaded .pdf file of M.M. Mousa and S.F. Ragab, Z. Naturforsch. 63a, 140 – 144 (2008) removed for copyright reasons]

## Float undefined while solving system of linear equ...

Dear Users,

I am solving a large system of linear equation with the Hybrid solver. Up to 2400 equations, I get a solution, but if I change the number of equations to 3000, I don't get any solution in fact solution entry reads Float(undefined). All the entries in matrix and vector are floating point decimal with 32 digits of accuracy. Any idea how to overcome this?

thanks.

i attach my file

maple_pita_he.mw

## How can I transfer the results of fsolve to an ass...

Suppose I have

solution:=fsolve(f(x,y)=0,x,y)

this returns

x=<result>, y=<result>

I want to continue the computation in my worksheet by assigning values to x and y without copying the numerical values by hand.

x:=<result>

y:=<result>

Then I want to make more computations with x and y.

It is too time consuming to copy the numbers by hand each time I run the worksheet

Larry

And y

## evalhf Int not working...

In the following case evalhf Int not working. Please help

evalhf.mw

## Symbolic PDE solve with BCs...

Having problems with solving PDE with symbolic BCs.

u(x,y,t,M,A);

M,A,x are constants for this problem.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>Code Starts

pde := diff(u(x, y, t), t)-.5*(diff(u(x, y, t), y, y))-A*sin(M*x-t) = 0

bc[1] := u(x, 0, t) = 0

bc[2] := u(x, 10, t) = A*sin(M*x-t)

sys := [pde, bc[1], bc[2]]

pdsolve(sys)

>>>>>>>>>>>>>>>>Code ends

I don't get any solution after this.
Moreover, in the second BC, I would like to change 10 to inifnity.

Thank you in advance for your help.

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