Ask Question
20 July, 14:51

Use the Laplace transform to solve the initial value problem"3y + 2y=0, y (0) = 1, y (0) = 0.

+5
Answers (1)
  1. 20 July, 15:07
    0
    Y (s) = 2 / (s+2) - 1 / (s+1)

    y (t) = 2e^ (-2t) - e^ (-t)

    Step-by-step explanation:

    Let's solve y'' + 3y' + 2y = 0, by the Laplace transform.

    So, the first step is to find the Laplace transform of each component of the differential equation

    L{y'' (t) } = s^2Y (s) - sy (0) - y' (0) = (s^2) Y (s) - s

    L{3y' (t) } = 3L{y' (t) } = 3 (sY (s) - y (0)) = 3sY (s)

    L{2y (t) } = 2L{y (t) } = 2Y (s)

    So now we have to solve the following equation:

    (s^2) Y (s) - s + 3sY (s) + 2Y (s) = 0

    Y (s) (s^2 + 3s + 2) = s

    Y (s) (s+2) (s+1) = s

    Y (s) = (s / (s+2) (s+1))

    Now to find y (t) and solve the initial value problem, we need to do the inverse Laplace transform of Y (s), that we can do the following way:

    Y (s) = (s / (s+2) (s+1)) = (A / (s+2)) + (B / (s+1))

    where A = s / (s+1) when s = - 2, so A = 2

    B = s / (s+2) when s = - 1, so B = - 1

    So

    Y (s) = 2 / (s+2) - 1 / (s+1)

    Doing the inverse Laplace transform

    y (t) = 2e^ (-2t) - e^ (-t)
Know the Answer?
Not Sure About the Answer?
Find an answer to your question 👍 “Use the Laplace transform to solve the initial value problem"3y + 2y=0, y (0) = 1, y (0) = 0. ...” in 📗 Mathematics if the answers seem to be not correct or there’s no answer. Try a smart search to find answers to similar questions.
Search for Other Answers