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anonymous
 one year ago
Differential equations question !
anonymous
 one year ago
Differential equations question !

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anonymous
 one year ago
Best ResponseYou've already chosen the best response.0\[3\frac{d^3y(t)}{ dt }+\frac{ dy(t) }{ dt }+2y(t)=u(t)\]

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0where u(t) has this form : dw:1436021576568:dw

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0and I must calculate :\[\int\limits_{0}^{5}y(t) dt\]

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0@oldrin.bataku never used that before but my question is: Does my diff eq has two solutions: y1(t) for t [0,2] y2(t) for t>2 ??

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0\[\int\limits_{0}^{5}y(t)dt=\int\limits_{0}^{2}y1(t)dt+\int\limits_{2}^{5}y2(t)dt\]

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0there are distinct solutions, but you need ICs to 'glue' them together

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0what's ICs ? Am I right with this distinct solutions ?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Initial conditions do you mean right ?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Can someone please guide me to all the steps needed(ICs,...) to help me understand this problem !

beginnersmind
 one year ago
Best ResponseYou've already chosen the best response.0"and I must calculate : ∫05y(t)dt" Maybe you don't need to solve the differential equation in general then

beginnersmind
 one year ago
Best ResponseYou've already chosen the best response.0If you express y(t) and integrate both sides from 0 to 5 you get a much simpler problem.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0can you be more specific please

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I mean how can I express something I don't know ? y(t) is the solution of that equation

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I forgot that the ICs are considered null.

beginnersmind
 one year ago
Best ResponseYou've already chosen the best response.0It's just an idea but I think it works dw:1436022843809:dw

beginnersmind
 one year ago
Best ResponseYou've already chosen the best response.0Assuming all derivates at 0 are zero, I get: dw:1436023098647:dw

beginnersmind
 one year ago
Best ResponseYou've already chosen the best response.0Where the integral with u(t) is known.

beginnersmind
 one year ago
Best ResponseYou've already chosen the best response.0Ok, not sure how to make progress from here. Maybe it doesn't work after all :(

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0@ganeshie8 any idea ?

ganeshie8
 one year ago
Best ResponseYou've already chosen the best response.0is the order really 3 ?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0actually I don't need to solve this eq but rather I need to know if my presumption is right that the eq got two distinct solutins depending on u(t); am I right ?

ganeshie8
 one year ago
Best ResponseYou've already chosen the best response.0particular solution changes depending on u(t) but the homogeneous solution remains same

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0well than I will reformulate the problem

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0this eq needs to be solved using numerical analysis method RUNGEKutta in MatLab so I must transform this equation in a first degree equations

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0@dan815 are you familiar with matlab or numerical analysis ?

dan815
 one year ago
Best ResponseYou've already chosen the best response.3first order runge kutta = euler method right

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0My question is if in my script of matlab do i need 2 functions: x1=Ax+5*b and x2=Ax+cos2t*b

dan815
 one year ago
Best ResponseYou've already chosen the best response.3and you have no initial values?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Intial conditions are considered null

dan815
 one year ago
Best ResponseYou've already chosen the best response.3okay so first write a bunch of first order ODes

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0That's for transforming the equation in a first order ODE

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Yeah right I think we should keep my notation as we are talking about vectors here: dw:1436025828612:dw

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0the matrix A that I telled you behind looks like this 0 1 0 0 0 1 2/3 1/3 0

dan815
 one year ago
Best ResponseYou've already chosen the best response.3why are you putting it in a matrix

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0x1=Ax+5*b and x2=Ax+cos2t*b dw:1436026153233:dw

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0MATRIXlaboratory a.k.a MatLab

dan815
 one year ago
Best ResponseYou've already chosen the best response.3if you want to solve it all in one matrix then, ud need it in the form like

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0script: function x1=FCS(t,y) x1=A*x+b*5; end function x2=FCS(t,y) x2=A*x+b*cos(2t); end

dan815
 one year ago
Best ResponseYou've already chosen the best response.3im wondering if this is really possible in this case hmm

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0dan I know that I'm just trying to understand my teacher method

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0dw:1436026645952:dw

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0than she makes a function : function xp=FCS(t,y) xp=A*x+b*u(t); end

dan815
 one year ago
Best ResponseYou've already chosen the best response.3so she got a new variable for x3

dan815
 one year ago
Best ResponseYou've already chosen the best response.3so that she doesnt have to worry about the extra vector

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0then she does another script for the y function