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A particular population P(t) of insects is modeled by the differential equation:dp /dt = kP-0.1P² where k is a constant. Find the general solution for P(t) in terms of k. You can proceed to find the general solution for the given differential equation in terms of the constant k.

User RishiG
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Final answer:

To solve the differential equation dp/dt = kP - 0.1P², we apply separation of variables and integrate both sides. The general solution involves partial fraction decomposition and leads to a logarithmic function, resulting in the population formula P(t) = k/(0.1 + Ce^{-kt}) with C as the constant of integration.

Step-by-step explanation:

To find the general solution of the differential equation dp/dt = kP - 0.1P², we can use the method of separation of variables. This method involves rearranging the equation so that all terms involving P are on one side and all terms involving t are on the other side. The separated equation can then be integrated with respect to P and t respectively.

The first step is to separate the variables:

\(\frac{1}{P(k - 0.1P)}\,dp = dt\)

Next, we integrate both sides:

\(\int \frac{1}{P(k - 0.1P)}\,dp = \int 1\,dt\)

This integral can be tricky but it can be solved by partial fraction decomposition. Assuming that k is not equal to zero, we can rewrite the left-hand side as two separate fractions:

\(\frac{A}{P} + \frac{B}{k - 0.1P}\)

After finding A and B by equating coefficients, the integral becomes a sum of two simpler integrals, typically resulting in logarithmic functions. After integrating and applying the constant of integration, we obtain an implicit solution for P(t).

The result is:

\(P(t) = \frac{k}{0.1 + Ce^{-kt}}\)

where C is the constant of integration, which can be determined by initial condition if provided.

The solution represents the population P(t) as a function of time t, and it incorporates the effect of both linear growth and a quadratic term that represents limitations such as resource competition affecting the population.

User Wjeshak
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