Solving exponential differential equations:

Cards (32)

  • What is the general form of exponential differential equations?
    dydt=\frac{dy}{dt} =ky ky
  • What are the steps in the method of separation of variables for exponential differential equations?
    1️⃣ Rearrange the equation to isolate dy on one side and dt on the other: dy/y = k dt
    2️⃣ Integrate both sides: ∫ dy/y = ∫ k dt
    3️⃣ Evaluate the integrals: ln(y) = kt + C
    4️⃣ Solve for y: y = Ce^(kt)
  • To integrate both sides of the equation `dy/y = k dt`, we get ln(y) on the left side.
  • Exponential differential equations model the rate of change of y proportional to its current value.

    True
  • In exponential decay, the value of k is negative.

    True
  • What constant replaces e^C in the final solution y = Ae^(kt)?
    A
  • In the exponential differential equation dy/dt = ky, the constant k represents the rate of growth or decay
  • The first step in the method of separation of variables for the equation dy/dt = ky is to rearrange the equation.
  • What is the integral of dy/y?
    ln|y| + C1
  • Exponentiating both sides of ln(y)=\ln(y) =kt+ kt +C C is a valid step in solving for y.

    True
  • What are initial conditions typically denoted as?
    y(0)=y(0) =y0 y_{0}
  • Steps to apply initial conditions y(t0)=y(t_{0}) =y0 y_{0} to find the constant A in y=y =Aekt Ae^{kt}
    1️⃣ Apply initial condition: y0=y_{0} =Aekt0 Ae^{kt_{0}}
    2️⃣ Solve for A: A=A =y0ekt0 \frac{y_{0}}{e^{kt_{0}}}
    3️⃣ Substitute A back: y=y =y0ekt0ekt \frac{y_{0}}{e^{kt_{0}}} e^{kt}
    4️⃣ Simplify: y=y =y0ek(tt0) y_{0}e^{k(t - t_{0})}
  • What is the value of A when the initial condition is y(0)=y(0) =y0 y_{0}?

    A = y_{0}</latex>
  • In the general form of exponential differential equations, the constant `k` represents the rate of growth or decay.
  • In exponential growth, the value of `k` is positive.
  • To solve for y in ln(y) = kt + C, we exponentiate both sides.

    True
  • After integrating both sides of the equation ln(y) = kt + C, the general solution for y is y = Ae^(kt).
    True
  • A negative k value in the equation dy/dt = ky indicates exponential decay.

    True
  • After solving for y in the equation ln(y) = kt + C, the simplified general solution is y = Ce^(kt)
  • What is the simplified form of y=y =ekt e^{kt} *eC e^{C}?

    y=y =Aekt Ae^{kt}
  • Steps to solve the differential equation dydt=\frac{dy}{dt} =ky ky
    1️⃣ Separate variables: dyy=\frac{dy}{y} =kdt k dt
    2️⃣ Integrate both sides: ln(y)=\ln(y) =kt+ kt +C C
    3️⃣ Exponentiate both sides: y=y =ekt+C e^{kt + C}
    4️⃣ Combine constants: y=y =Aekt Ae^{kt}
  • The specific solution to \frac{dy}{dt} = 2y</latex> with y(0)=y(0) =5 5 is y=y =5e2t 5e^{2t}.

    True
  • The steps to solve dydt=\frac{dy}{dt} =ky ky include separating variables, integrating both sides, and combining constants.

    True
  • In the final solution y=y =y0ekt y_{0}e^{kt}, y0y_{0} represents the initial value of y at t = 0
  • Steps in solving exponential differential equations using separation of variables
    1️⃣ Rearrange the equation to isolate variables: dy/y = k dt
    2️⃣ Integrate both sides: ∫ dy/y = ∫ k dt
    3️⃣ Evaluate the integrals: ln(y) = kt + C
    4️⃣ Solve for y: y = e^(kt + C)
    5️⃣ Simplify: y = Ce^(kt)
  • What type of rate does a positive k value represent in the equation dy/dt = ky?
    Growth
  • What is the result of integrating both sides of the equation dy/y = k dt?
    ln(y) = kt + C
  • Match the step with its outcome in the method of separation of variables:
    Rewrite the equation ↔️ ∫ dy/y = ∫ k dt
    Integrate both sides ↔️ ln|y| = kt + C
    Exponentiate both sides ↔️ y = Ae^(kt)
  • The constant eCe^{C} can be replaced with another constant, say A
  • In the example dydt=\frac{dy}{dt} =2y 2y and y(0)=y(0) =5 5, the first step is to separate the variables
  • The final solution to the differential equation dydt=\frac{dy}{dt} =ky ky is y=y =Aekt Ae^{kt}, where k is the constant rate of growth or decay
  • The final solution to dydt=\frac{dy}{dt} =ky ky with initial condition y(0)=y(0) =y0 y_{0} is y=y =y0ekt y_{0}e^{kt}.

    True