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Homework Help: Solving second order diff equ

  1. Oct 4, 2011 #1
    1. The problem statement, all variables and given/known data
    I have got the diff equ problem solved out to

    y(t)=Ce^-t*cos4t+Ce^-t*sin4t


    2. Relevant equations
    now I have to solve for the IVP and the values are y(0)=1, yprime(0)=-1


    3. The attempt at a solution
    I believe for the first part I just plug in the y(0)=1 which results in the e^-t dropping out
    coming out to be C=1 but I am not 100% on it.

    Then I am assuming I take the derivative and solve for the next value.
     
    Last edited: Oct 4, 2011
  2. jcsd
  3. Oct 4, 2011 #2

    SammyS

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    Are you sure those shouldn't be two different constants, as in y(t) = C1 e-t cos(4t) + C2 e-t sin(4t)

    Then, you found that C1 = 1.

    Now find y'(x) , then set y'(0) = -1 & solve for C2 .
     
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