Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.

S asked in Science & MathematicsMathematics · 4 years ago

Calculus help to solve the differential equation?

Solve the differential equation using the initial condition. Then find the exact value of f(1).

y = y - 1 y(0) = 3

I don t know how to do this so could you explain how to do this.

1 Answer

Relevance
  • 4 years ago
    Favorite Answer

    I'm guessing the y on the left side of the equal sign should be y'?

    y' = y - 1

    Write as dy/dx:

    dy/dx = y - 1

    Separate the variables (y's on one side and x's on the other):

    dy / (y - 1) = dx

    Integrate:

    ln |y - 1| = x + C

    Solve for y:

    y - 1 = e^(x + C)

    y = 1 + e^(x + C)

    y = 1 + e^x e^C

    e^C is just another constant, so:

    y = 1 + C * e^x

    Find C using the initial condition:

    3 = 1 + C * e^0

    2 = C

    Substitute:

    y = 1 + 2 * e^x

    Finding f(1):

    y = 1 + 2 * e^1

    y = 1 + 2e

Still have questions? Get your answers by asking now.