Trying to solve a first-order differential equation (Ramp Function in a Circuit)

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The discussion focuses on solving the first-order differential equation di/dt + 8i = 0.8t, derived from a Thevenin-reduced circuit with a ramp function as the input voltage. The user successfully found the homogeneous solution, i = Ae^(-8t), but is struggling to determine the particular solution given the initial condition i(0) = 0. Suggestions include using the method of undetermined coefficients or an integrating factor to find the particular solution. The conversation emphasizes the importance of correctly applying these methods to solve for i(t) in the context of the circuit. Overall, the thread seeks assistance in completing the solution to the differential equation.
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1. I am trying to find i(t) through an inductor in a thevenin-reduced circuit. I come down to the equation di/dt+8i=0.2v(t) where v(t) is the ramp function 4r(t).

2. So the simplified equation is di/dt+8i=0.8t.

3. I found the homogenous equation (i=Ae^(-8t)) but I cannot figure out how to get the particular solution. The initial condition is i(0)=0.

Thanks for any help
 
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Use the method of undetermined coefficients, or use an integrating factor to solve the differential equation.
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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