The particular solution of dy/dx = 2y + 6 is:
b. y = -3 + 2e^(-2x)
Explanation:
- The given differential equation is dy/dx = 2y + 6.
- To solve this linear first-order differential equation, we can apply the method of integrating factors.
- The integrating factor for this equation is e^(∫2dx) = e^(2x).
- Multiplying the given differential equation by the integrating factor, we get e^(2x)dy/dx - 2ye^(2x) = 6e^(2x).
- This can be rewritten as d(ye^(2x))/dx = 6e^(2x).
- Integrating both sides with respect to x gives ye^(2x) = ∫6e^(2x)dx = 3e^(2x) + C, where C is the constant of integration.
- Solving for y, we get y = 3 + Ce^(-2x).
- To find the particular solution, we use the initial condition that when x = 0, y = -3.
- Plugging in these values, we find that the constant C = -3.
- Thus, the particular solution is y = -3 + 2e^(-2x).
Therefore, the correct answer is option b: y = -3 + 2e^(-2x).