## 261 Reputation

17 years, 46 days

## Ztransform with initial conditions...

Maple

Is it possible to perform a Ztransform with initial conditions in Maple?

I want to calculate the Ztransfrom of following differrence equation.

Dv:=3*y(k)-4*y(k-1)+4*y(k-2)=(1/2)^k*Heaviside(k)

With.

y(-1) = 1

y(-2) = 2

For now I am using following command.

Opl:=ztrans(Dv,k,z);

I suppose that this command uses initial conditions zero.

## Problem with laplace transform...

Maple
I convert following differential equation to the s domain: restart: with(inttrans): > DV:=diff(y(t),t\$2)+3*diff(y(t),t)+2*y(t)=diff(x(t),t): > x:=t->10*exp(-3*t): > laplace(DV,t,s); As solution I get: s^2*laplace(y(t),t,s)-D(y)(0)-s*y(0)+3*s*laplace(y(t),t,s)-3*y(0)+2*laplace(y(t),t,s) = -30/(s+3) It's not really a Maple problem but I don't understand why the right hand side of the equation is -30/(s+3) . When I transform the right hand side of the differential equation manual to the laplace domain I would do it as: diff(x(t),t) = s*X(s) = s * 10 /(s+3)

## Solving a combined differential and inte...

Maple
Is there a way to solve following equation in maple? I have already tryied intsolve and dsolve without succes. DV:=diff(y(t),t)+5*int(cos(t-tau)*y(tau),tau=0..t)=10; Thank you, Pieter

## How to work around divided by zero?...

Maple
I have been trying to solve the following differential equation with 2 starting conditions. (It's the equation of a mechanical vibration). >diff(x(t), t, t)+4*Pi^2*x(t) = 200*sin(hoekvers*t) beginvw:=x(0)=5,D(x)(0)=0; The result: >Opl:=dsolve({DV,beginvw},x(t)); >Opl:=x(t) = -100*sin(2*Pi*t)*hoekvers/(Pi*(4*Pi^2-hoekvers^2))+5*cos(2*Pi*t)+200*sin(hoekvers*t)/(4*Pi^2-hoekvers^2) Now I want to plot the graphic of this vibration when hoekvers=2*Pi. (In that case there is resonance) I get the error dived by zero. As you see the numer is zero when I fill in 2*Pi. For 2*Pi+0.000000000001 I get no error and a good graphic but this is not a good and exact method according to me.

## How to insert text in worksheet mode....

Maple
I am using Maple since a year and I am used to work in the classic worksheet. Now I wanted to try out the regular worksheet (you also have document mode). This worksheet is completly different from the classic one. By example I can not find a way to insert text in that worksheet. I click 'text' (F5) then 'Maple Input' is highlighted. I change it to 'text' and type some text. I press enter and ' ";" is missing ' is displayed. This is just text not a Maple command... How can I let this sheet now I only want to insert text? Thanks in advance, Pieter
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